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A STUDY IN 
 
 Reaction Time and Movement 
 
 THOMAS VERNER MOORE, C.S.P. 
 
 A DISSERTATION 
 
 Submitted to the Faculty of Philosophy 
 
 of THE 
 
 Catholic University of America 
 
 in Partial Fulfilment of the Requirements for 
 
 the Degree, Doctor of Philosophy 
 
 WASHINGTON, D. C, 
 April, 1904 
 
A STUDY IN 
 
 Reaction Time and Movement 
 
 THOMAS VERNER MOORE, C.S.P. 
 
 A DISSERTATION 
 Submitted to the Faculty of Philosophy 
 
 of THE 
 
 Catholic University of America 
 
 in Partial Fulfilment of the Requirements for 
 
 the Degree, Doctor of Philosophy 
 
 WASHINGTON, D. C. 
 April, 1904 
 
^ 
 
 
 PlCSt OF 
 IlllHfUfll'IfC 
 
 LAtCAlTEI. P*. 
 
 Gift 
 TU University 
 
 4MyW 
 
CONTENTS. 
 
 Page. 
 
 I. Introduction , , i 
 
 II. Literature 4 
 
 III. Statement of the Problem 10 
 
 IV. Description of Apparatus 13 
 
 V. Experimental Results 17 
 
 1. Reaction time and speed of movement, subject unin- 
 
 structed 17 
 
 2. The same, subject instructed to respond with quickest 
 
 possible movement 20 
 
 3. Reaction with lever, without intentional regard to speed.... 27 
 
 4. Effect of practice on movement time 30 
 
 5. Effect of varying preliminary signal 31 
 
 6. Series with irregular or no signal 33 
 
 7. Series with no signal, subject adding 35 
 
 8 . Compound reaction and speed of movement 40 
 
 9. Movement of reaction and an independent voluntary 
 
 movement 43 
 
 10. Effect of stimuli and time of reaction and of movement 45 
 
 11. Graphic curve of the movement 53 
 
 Summary 55 
 
 VI. Theoretical Interpretations 58 
 
 1. Physiological interpretation of contancyof movement time. 58 
 
 2. Physiological interpretation of variation of movement 
 
 under the influence of sensory stimuli 61 
 
 3. Bearing of the experiments on Miinsterberg's Action-Theory 62 
 
 a. Outline of the theory 63 
 
 b. Criticism of the theory 67 
 
 4. Motor center employed in reaction 72 
 
 5. Distinction between muscular and sensorial reactions 77 
 
 Bibliography , 81 
 
BIOGRAPHY. 
 
 The author of this dissertation was born in Louisville, Ky., 
 October 22, 1877. He passed through the grammar schools in 
 that city and commenced his classical studies at St. John's Col- 
 lege, Fordham, N. Y., in January, 1891. The following scho- 
 lastic year he resumed these studies at St. Francis Xavier's 
 College in New York City, remaining there until about the 
 middle of his Freshman year, in 1894. He entered the Catholic 
 University of America in January, 1897. While studying phi- 
 losophy and theology in St. Thomas' College, he carried on 
 studies in psychology, logic, mathematics and the natural 
 sciences, at the University. He was ordained a priest of the 
 Congregation of St. Paul the Apostle, December 21, 1901. He 
 pursued courses under Dr. Pace, Dr. Shields, Dr. Shanahan, 
 Dr. Greene, Dr. Griffin, Dr. Shea, and Mr. Doolittle, and was 
 a member of the seminars held by Dr. Pace, Dr. Shields, and 
 Dr. Shanahan. 
 
I. INTRODUCTION. 
 
 The problem of reaction time has already been studied by 
 many psychologists of great merit. The various influences 
 which lengthen or shorten reaction time have been worked out, 
 and at first sight it would seem a most unpromising field of 
 research. And if the attempt had been made to study reaction 
 time alone, it is scarcely probable that anything new and im- 
 portant could have been brought to light. But while reaction 
 time itself has been quite thoroughly studied, the movement by 
 which the reaction is made has received but little attention. 
 This neglect has arisen, in all probability, from the fact that 
 when the problem of reaction time was being actively discussed 
 the attention of psychologists was focused upon representative 
 and not upon motor processes. Only of late years has move- 
 ment come to the foreground, as an object of psychological 
 study. Motor processes are being recognized more and more 
 as important elements in conscious processes. Professor Miin- 
 sterberg has even gone so far as to assert that consciousness is 
 absolutely dependent upon the possibility of a motor discharge. 1 
 
 The evident endeavor which asserts itself in many quar- 
 ters to bring in motor processes to explain the fact of con- 
 sciousness, makes it all the more important that they should be 
 the object of experimental research. And on this account, too, 
 a study in the psychology of movement has a value over and 
 above whatever technical merits it may possess. Even purely 
 physiological and anatomical studies of movement are found to 
 have their paths of connection — long perhaps, but clearly 
 marked — with the broader highways of philosophical inquiry. 
 For whether the new theories are right or wrong, they will not 
 and ought not to be laid aside, till subjected to the most search- 
 ing and critical tests. And in the very nature of the case the 
 study of movement will be of prime importance in the confirma- 
 tion or rejection of any theory of consciousness which rests 
 upon motor processes as the very groundwork of its structure. 
 
 1 ■ Grundziige der Psychologies Vol. I., p. 530. 
 
2 THOMAS V. MOORE. 
 
 The phenomenon of reaction seems to offer peculiar advan- 
 tages for this study. Kiilpe defines reaction as the ' answer 
 given to a sensory impression by means of movement.' ! Whether 
 or not this movement comes as the result of conscious processes, 
 or accompanies or perhaps precedes them, is a matter of dis- 
 cussion. Cattell persists in looking upon all reactions as a kind 
 of reflex. He defines and analyzes the process as follows : 
 4 'The reaction time is the interval elapsing before a prede- 
 termined movement follows on a predetermined stimulus. Dur- 
 ing this interval a series of physiological processes takes place. 
 (i) The stimulus is converted into a nervous impulse ; (2) the 
 nervous impulse travels along the sensory nerve and, it may be, 
 the spinal cord to the brain ; (3) through sensory tracts of the 
 brain to a sensory center ; (4) changes occur in this center : 
 these changes are followed by a discharge from a motor center ; 
 
 (6) the motor impulse travels along motor tracts in the brain ; 
 
 (7) along the motor nerve and, it may be, the spinal cord, and 
 finally, (8) the muscle is innervated. The process is probably 
 an acquired cerebral reflex, not accompanied by conscious! 
 The stimulus is indeed perceived, but probably not before the 
 motor impulse has been discharged. The stimulus causes two 
 sorts of cerebral changes, the discharge of the motor impulse, 
 and changes in the cortex, which are accompanied b ious- 
 ness. But, contrary to the views of most psychologists, we 
 think the movement does not follow on changes in conscious- 
 ness, but is stimultaneous with, or actually prior to them. What 
 volition is concerned in the process precedes the reaction and 
 consists in preparing the motor impulse which is reilexly dis- 
 charged." 2 
 
 Directly opposite to this analysis of reaction time is that of 
 Wundt. According to him, reaction time is made up of the 
 following processes : " (1) Conduction from the organ of sense 
 to the brain ; (2) entrance into the held of consciousness ; (3) 
 entrance into the focal point of consciousness ; (4) the stimula- 
 tion of the will, which sets free the motion registered in the 
 central organ ; and (5) conduction of the motor discharge thus 
 
 ^Grundriss der Psychologies Leipzig, 1S93, p. 421. 
 
 2 National Academy of Sciences, Vol. VII., pp. 393-394. 
 
REACTION TIME AND MOVEMENT. 3 
 
 arisen to the muscles and the increase of energy in them." ! The 
 process of reaction here analyzed Wundt looks upon as com- 
 plete ; and it is termed by him a sensory reaction. When, how- 
 ever, the attention is focused upon the reacting organ, a short- 
 ened form of reaction takes place which, according to Wundt, 
 corresponds to the analysis given by Cattell. This form of re- 
 action Wundt terms muscular, still adhering to the distinction 
 pointed out by L. Lange in 1888. 
 
 In an article communicated to Mind in January, 1903, 2 Mr. 
 W. G. Smith called attention to another factor which has a 
 bearing upon the analysis of the reaction process. He found 
 that with some subjects, before the prearranged reaction move- 
 ment commenced, there was a preliminary movement in the 
 opposite direction. This antagonistic movement consumed from 
 four to five hundredths of a second and occurred in various 
 muscles and with various movements. With some subjects it 
 occurred constantly, with others but rarely or not at all. Physio- 
 logically he attributed this to a prior contraction of the antagon- 
 ists. This was an involuntary adjustment calculated to produce 
 a forcible movement rather than a sudden start. Psychologi- 
 cally, he referred the phenomenon to the dominance of the idea 
 — first holding possession of consciousness — to hold the finger 
 pressed down upon the key. A further consideration of this 
 problem and its bearing on our results, will be taken up later. s 
 We shall now pass on to an account of the literature bearing 
 more particularly upon the problem under discussion. 
 
 ^Grundziige der physiologischen Psychologie, ' 4th ed., Vol. II., p. 306. 
 Cf. also 5th ed., Vol. Ill, p. 384. 
 
 2 ' Antagonistic Reactions,' pp. 47-58. 
 3 Infra, p. 55. 
 
II. LITERATURE. 
 
 Since the question of reaction time is only subsidiary to our 
 real problem, it will not be necessary to give in this paper an 
 account of its rather extensive literature. References, however, 
 to the various accounts of the literature of reaction time will be 
 given in the bibliography. The motor discharge by which the 
 reaction is made has been studied but little. Most of the pre- 
 vious investigations in this field of research have been concerned 
 separately with one or the other of the two phenomena into 
 whose relation we now inquire. Movement has been given a 
 great deal of attention in studies of fatigue. The perception of 
 movement and its accuracy have also been the subject of much 
 research. 
 
 In a paper communicated to the Royal Society of Lon- 
 don, 1 Dr. William R. Jack presented a study of the velocity 
 of various finger movements for people of different pursuits and 
 ages. No comparison of the velocity of movement with the 
 time of reaction was made. Only the speed of movement was 
 studied and its variation according to the age and ordinary life 
 of the subject. 
 
 Dr. J. B. Haycraft published an article, 2 4 Upon the Pro- 
 duction of Rapid Voluntary Movements,' in 1S9S. He meas- 
 ured the time of flexion of the middle finger and also found that 
 the velocity of a movement checked in its initial stage was almost 
 four times greater than that of a movement made in the ordinary 
 way. 
 
 The literature which bears upon the relation between reac- 
 tion time and the subsequent movement is not extensive. The 
 problem was mentioned in a doctorate dissertation by C. B. 
 Bliss, published in the * Studies from the Yale Psychological 
 Laboratory* in 1893. "In connection," he writes, " with these 
 experiments where the attention was directed to a motion for 
 which the reaction was a means, the idea suggested itself, but 
 
 1 Proc. of the Royal Soc. of London, Vol. L,VIL, 1S95, pp. 477-4S1. 
 2 fournal of Physiology, 1S9S, Vol. XXIII., pp. 1-9. 
 
 (4) 
 
REACTION TIME AND MOVEMENT. 5 
 
 has not yet been carried out, of having a second reaction key 
 in place of the point on the table. Then we should have re- 
 corded, in addition to the reaction time, the time required to make 
 a certain movement. This would probably vary from time to 
 time, with changing mental and physical conditions. None of 
 its variations could be attributed to influences acting upon the 
 conscious part of the reaction, for it would be purely automatic 
 after slight practice. This might throw some light on the rela- 
 tive portion of the variation which is to be assigned to the purely 
 psychical part. Possibly it might be used instead of simple re- 
 action as a standard for comparing different kinds of reaction 
 time/' 1 Dr. Bliss made experiments in which "the reaction 
 consisted in touching a point on the table six inches from the 
 key. Raising the finger from the key to make this motion 
 broke the spark coil circuit and so only the beginning of the 
 motion was registered. Here again the mind was mistaken in 
 judging that the reaction time was quicker than usual." 
 
 As early as 1889 2 M. Charles Fere, who has given us a 
 number of studies in movement, undertook to investigate the re- 
 lation between the time of reaction and the force of movement. 
 He made three sets of experiments. The first was on subjects 
 suffering from hysteria. With these subjects there was a de- 
 cided difference between the pressures which the two hands 
 were capable of exerting separately. It was found that the 
 hand which gave the strongest dynamometric pressure reacted 
 more quickly than the other. Furthermore, under the influence 
 of pleasurable emotions, which were suggested to the subjects, 
 the dynamometric pressure was strengthened and the reaction 
 time quickened. The odor of musk strengthened both hands 
 considerably and notably shortened the reaction time. The 
 second series of experiments was made on epileptics. After an 
 attack of epilepsy these subjects suffer a decided loss of muscu- 
 lar power. Reaction times measured after such attacks were 
 considerably lengthened. The third series of experiments was 
 made on normal subjects, with the aid of a specially constructed 
 dynamometer, which could measure the force of fifty different 
 
 1 Op. cit. y p. 37. 
 
 2 Revue Philosophique, Vol. XXVIII., pp. 36-69. 
 
6 THOMAS V. MOORE. 
 
 movements of flexion and extension of the muscles which con- 
 trol the movements of the hand. The reaction time was meas- 
 ured by the d'Arsonval chronometer. It seems that the meas- 
 urements of pressure and extension were taken in separate 
 series, since the author does not tell us of any attempt to obtain 
 the pressure of the actual movement of reaction. Ke sought to 
 investigate the relation between the force a given muscle or a 
 set of muscles was capable of exerting and the speed with which 
 it could react. The signal for reaction was a touch on the 
 back of the hand, the eyes of the subject being closed. The 
 results obtained seemed to indicate that the time of reaction was 
 a little quicker according as the muscles involved were capable 
 of exerting greater force. In another set of experiments the 
 recording apparatus consisted of a Marey signal, two tambours 
 and a tuning-fork. By this apparatus it was shown (a) that the 
 time of reaction for the left hand was slower than that of the 
 right ; (b) that the sum of the reaction times of both hands was 
 greater when the attempt was made to react simultaneously, 
 than when they reacted successively. M. Fere considered a 
 similar conclusion as established, namely, that the sum of the 
 pressure of the two hands is greater when each acts successively 
 than when both act together. From these two results M. 
 Fere deduced the law that the rapidity and amount of nervous 
 discharge are greater according as the outlets are less numerous. 
 
 In 1889, Dr. J. Orschansky touched directly upon the re- 
 lation between reaction time and the subsequent movement, 
 while investigating the nature of inhibition. 1 The amount of 
 muscular movement in reaction, he says, is composed of two 
 factors if we abstract from its velocity. These two factors are 
 the intensity of muscular contraction and its amplitude. He 
 determined the intensity of muscular contraction by making the 
 masseter react against springs of three different strengths. He 
 merely tells us that the amplitude of the contraction was re- 
 corded by the Marey tambour. But just how the extent of 
 movement was limited — whether mechanically or by accident 
 or by the subject's judgment — is not stated. He found that 
 the most favorable conditions for a quick reaction were present 
 when either the tension of the springs was at a minimum and the 
 
 x Archiv filr Physiol ogie [dm Bois-Rc 1SS9, PP- I 73 _I 9 S - 
 
REACTION TIME AND MOVEMENT. 7 
 
 amplitude at a maximum, or the tension at a maximum and the 
 amplitude at a minimum. This he explained by saying that the 
 quantity of tension in the apparatus acted as a sensorial stimu- 
 lus for the attention, while the idea of the extent of movement 
 was an element in the motor representation which preceded the 
 reaction. If, however, neither tension nor amplitude was at a 
 maximum or a minimum, it was found that the reaction time 
 was lengthened. This was explained on the ground that in 
 such cases the attention had to deal with more complicated con- 
 ditions. In the former case the psychic act of reaction con- 
 sisted of one factor at a maximum while the other was excluded. 
 In the latter case the attention had to deal with both factors. 
 It is to be regretted that Dr. Orschansky did not give us a more 
 detailed account of his experiments and furnish us with data 
 concerning the number of experiments and their mean variation. 
 For it is hard to pass judgment on the value of the results from 
 the paper in its present form. 
 
 In 1892 l M. Ch. Fere studied the relation of reaction time 
 to the weight lifted in reacting. He arrived at the following 
 conclusions : 
 
 For one and the same subject the reaction time is longer 
 according as the weight to be lifted is heavier — provided that 
 the weight is not known beforehand. 
 
 When, however, the weight to be lifted is known to the sub- 
 ject beforehand the length of reaction time does not vary 
 regularly with the weight, but with the capability of the subject 
 to adapt his attention. 
 
 Deceiving the subject as to the weight to be lifted affects 
 the reaction time. If he expects a light weight and has to 
 move a heavy one, the reaction time is lengthened and the 
 ascent of the curve of movement is very oblique. If the re- 
 verse happens, the reaction time is shortened and the ascent of 
 the curve of movement is vertical. 
 
 The time of reaction for letting a weight fall is shorter than 
 for lifting a weight. 2 
 
 1 Comptes Rendus de la Societe de Biologie, 9th Series, Vol. IV., 1892, pp. 
 
 432-435- 
 
 1 This result is not against that of Dr. Orschansky, for antagonistic muscles 
 are involved in raising and lowering a weight. In Dr. Orschansky's experi- 
 ments merely the contraction or relaxation of the masseler was involved. 
 
8 THOMAS V. MOORE. 
 
 The heavier the weight the longer the reaction time of re- 
 laxation if the weight has not been supported long. 
 
 If it has been supported from one to two minutes, the longer 
 it has been supported the longer will be the reaction time. 
 After the onset of fatigue, however, the reaction time is short- 
 ened. M. Fere explains this last result by saying that the sub- 
 ject has already commenced to relax when he hears the signal. 
 
 The results of M. Fere seem to be at variance with one of 
 the conclusions of Awramoff, whose work is mentioned below. 
 This writer found that the quicker reaction time is obtained 
 when the heavier weight is to be lifted. He made no attempt 
 to harmonize his results with those of M. Fere. But some ex- 
 planation of the difference may be sought in the rapidity with 
 which Awramoff's experiments followed one upon another. 
 
 In Volume XVIII. of the Philosophische Studicn ' Dobri 
 Awramoff published an article entitled * Arbeit und Rhythmus.' 
 The second part of this article is a study of reactions made by 
 lifting weights. The subjects lifted a weight of three kilograms 
 in most of these experiments. The apparatus used was an 
 ordinary ergograph. He found that when the signals to react 
 are given rhythmically (e. g., every two seconds) the subject 
 reacts more quickly than when the signals come at irregular 
 intervals. He explained this phenomenon on the ground of the 
 distinction between muscular and sensorial reaction. Irregular 
 intervals between the stimuli make it more necessary for the 
 subject to be on the lookout for the signal. But regular inter- 
 vals occasion the subject to keep up a motor preparation for the 
 movement. He also found that a rhythm of one second gave 
 rise to a quicker reaction than a rhythm of two seconds. The 
 reaction time for raising a weight of five kilograms was shorter 
 than that for raising a weight of three kilograms. The reaction 
 times being measured by the graphic method, a curve of the 
 movement was obtained from which the author was able to arrive 
 at several conclusions. The length of time the weight is held 
 up is longer for non-rhythmic than for rhythmic reactions. The 
 height to which the weight was lifted was greater for non- 
 rhythmic than for rhythmic reactions. It was also claimed that 
 the form of the curve was indicative of individual peculiarities. 
 
 1 Pp. 515-562. 
 
REACTION TIME AND MOVEMENT. 9 
 
 As a preliminary to a more complete paper on the study of 
 temperament, Prof. E. B. Delabarre communicated an article 
 * On the Force and Rapidity of Reaction Movements ' to the 
 Psychological Review in November, 1897. * The object of 
 the experiments was to determine the individual peculiarities in 
 the subject's manner of reacting. The subject's attention was 
 therefore turned away as far as possible from the reacting move- 
 ment itself so as to leave it perfectly natural and spontaneous. 
 The apparatus used recorded the reaction time, the pressure of 
 the reaction movement, and the duration of that part of the 
 movement during which the pressure of the reacting muscles 
 increased in intensity. It was found that the ratio of pressure 
 to duration time tended in any one series to constancy. Several 
 individual peculiarities were pointed out, but no fixed relation 
 was found between reaction time and either the pressure or the 
 duration of the pressure. 
 
 1 Vol. IV., pp. 615-631. 
 
III. STATEMENT OF THE PROBLEM. 
 
 The results just mentioned from Professor Delabarre and 
 his associates were just what we should antecedently expect. 
 If the force of movement is left to accident and individual tem- 
 perament, there is no a -priori probability that a constant ratio 
 will be found between the time of reaction and the force of the 
 subsequent movement. It was essential to the study of temper- 
 ament, however, that the force of movement should not be pre- 
 determined by special choice. But over and above any question 
 of individual temperament, there is another which is presented in 
 a study of the movement by which a reaction is executed. This 
 movement is the manifestation of the motor discharge by which 
 the reaction is executed. It is the immediate result of the efferent 
 and central processes in reaction, and can perhaps be made to 
 throw some light on several problems in general psychology. 
 But in order that this may be done, the motor discharge must 
 not vary with the accidents of temperament and transient con- 
 ditions. For the large accidental variations taking place under 
 such conditions would altogether obscure the lesser fluctuations 
 which might be due to disturbances of the attention, interpolated 
 psychical processes, sensory stimuli, etc. 
 
 Some kind of constant must evidently be the basis of our 
 comparison, and in this case the only constant possible is the 
 subject's maximum effort. One is fairly sure of sending the 
 maximum discharge from the motor center ; but even after long 
 practice it would scarcely be possible to be sure of dividing that 
 discharge into any constant fraction. Whether or not our 
 maximum effort is a merely subjective constant varying in its 
 objective manifestation from moment to moment, is a problem 
 which experiment alone can determine. But at all events, the 
 subject's maximum effort should be constant to serve as our 
 basis of comparison. The factor most likely to cause its objective 
 manifestation to vary is fatigue. Fatigue would therefore enter 
 into the results as an undesirable factor. It would obscure those 
 
 (10) 
 
REACTION TIME AND MOVEMENT. II 
 
 lesser variations which might be due to disturbances or stimuli 
 whose effect we seek to measure. In order, then, to eliminate 
 this undesirable factor as far as possible, it is necessary to study 
 the maximum speed of an unresisted movement rather than the 
 maximum force which any given muscle or set of muscles could 
 exert in a single contraction. The maximum rapidity of a 
 movement is just as much the index of a motor discharge as its 
 maximum force, and in all probability it represents a simpler 
 discharge — approaching as near to a unit discharge as any 
 voluntary contraction can possibly do. For these reasons it 
 was decided to take the maximum speed of an unresisted move- 
 ment, made in response to a stimulus to react as the basis of our 
 study rather than the stronger force of movement. The funda- 
 mental problem of the whole inquiry thus took on this form : 
 When the attempt is made to react with the quickest -possible 
 movement, is there any relation between the time of reaction and 
 the speed of the movement? 
 
 The first step in the solution of this problem is evidently the 
 choice of a movement for reaction which will serve best the 
 scope of the present investigation. In previous investigations 
 of reaction time, a number of movements have been selected by 
 which the subject responded to the incoming stimulus. M. 
 Fere, as we have said, investigated the reaction time for each of 
 the fingers. Cattell has studied that of the finger, wrist, fore- 
 arm, shoulder, 1 and foot. 2 And in some pieces of work suffi- 
 cient attention has not always been paid to stating by just what 
 movement the subject reacted. Cattell's results showed a dif- 
 ference between the reaction times of the wrist, forearm and 
 shoulder. And when a subject is told to press down upon or to 
 raise his finger from a telegraph key there are various muscles 
 and combinations of muscles which might be brought into play 
 unless some precautions are taken to insure the same movement 
 each time the subject reacts. While the lack of such precau- 
 tions in ordinary experiments on reaction time would be only a 
 minor defect, it would certainly be more serious in a study which 
 
 1 ' On Reaction Time and the Velocity of the Nervous Impulse,' Nat. Acad, 
 of Sciences, Vol. VII., p. 410. 
 
 2 Loc. cit. y p. 404. 
 
12 THOMAS V. MOORE. 
 
 investigates the relation between reaction time and the speed of 
 movement by which it is executed. For purposes of the present 
 work it is of prime importance to secure the same movement 
 throughout the entire series of experiments, unless special reason 
 intervenes for changing its extent or abandoning it for some other. 
 
 The method of experiment suggested by Dr. Bliss for the 
 investigation of this problem would have been open to several 
 objections. In the first place, the path of movement would be 
 subject to endless variation. In lifting the hand from one key 
 to another the arm might be raised six inches or more, or pass 
 almost in a straight line from one key to another. In the second 
 place, varying combinations of fingers, wrist, forearm, and 
 shoulder might be called into play, in order to touch the second 
 telegraph key. And besides, there would be present a disturb- 
 ance of a psychological character in the care that would have 
 to be taken lest the second key should be missed. 
 
 One desirable feature in the movement is that its possible 
 path should be of considerable extent, so that it can be measured 
 with accuracy and also be lengthened or shortened should the 
 experimenter so desire. But in itself there is no reason 
 why one movement has any particular advantage over another 
 — so long as the same movement is secured throughout. The 
 speed of the subsequent movement is studied as an index of 
 the motor discharge, which passes down from brain to muscle. 
 Different cortical areas will of course be involved when differ- 
 ent movements are made. But the motor discharge of one cor- 
 tical area is just as good for our present purpose as that of any 
 other. But it would be fatal to change, without knowing it, 
 in the same series of experiments from one cortical area to 
 another. This would subject the experiments to hidden varia- 
 tions and render trustworthy interpretations impossible. 
 
 After some consideration the movement decided upon was 
 an outward rotation of the humerus. In this movement there is 
 no work done by lifting the arm from one plane to another, and 
 the apparatus used supported the arm, so that, as far as possible, 
 the muscles were free from all resistance. This eliminated any 
 complications which might arise from fatigue. Nor did the 
 results obtained indicate they were in any way influenced by the 
 onset of fatigue. 
 
IV. DESCRIPTION OF APPARATUS. 
 
 The apparatus devised for the measurement of this move- 
 ment was quite simple. A brass rod 53.2 cm. long and 14 
 mm. in diameter was pivoted at one extremity on a metal sup- 
 port which rested on a large semicircular wooden base of about 
 the same radius as the rod. Near the pivoted end of the rod 
 there was a semicircular brass rest (lined inside with felt) to 
 support the elbow. Toward the other end of the rod there was 
 an upright handle which the subject grasped with his right 
 hand. This handle could be moved up or down the brass rod 
 and fixed by means of a screw, to suit the length of arm of the 
 subject under experiment. In one corner of the wooden base 
 there was a metal post, through which an electrical contact was 
 made with the lever, if the circuit were elsewhere closed. So 
 slight was the friction of the pivoted lever that the least move- 
 ment of the subject's arm sufficed to break this contact. This 
 occasioned some trouble at first, for the subject unwittingly 
 broke and remade contact several times before the signal to re- 
 act. This could have been obviated by instructing him to keep 
 the lever lightly pressed against the metal post until the signal 
 to react. Such a scheme, however, would have introduced 
 some sort of error. For at the beginning of the movement the 
 antagonistic muscles would have to be relaxed and their resist- 
 ance overcome. The amount of this resistance would also vary 
 in each experiment, according as the subject pressed more or 
 less heavily against the post. Accordingly a latch was devised 
 to obviate the difficulty. A V-shaped piece of brass was piv- 
 oted on a metal post stationed at the edge of the wooden base. 
 A steel spring was hung between a shoulder on this piece of 
 brass and a hook on the wooden base. When the lever was at 
 the post, one arm of the V-shaped piece of brass rested against 
 its exterior side and by means of the spring the lever was kept 
 in contact with the post. The resistance exerted by this spring 
 to the start of the movement was too slight to be felt by the 
 
 (13) 
 
1 4 THOMAS V. MOORE. 
 
 subject, but it sufficed to keep the contact made until the move- 
 ment of reaction. Only a part of the movement made was 
 recorded, because its absolute length was subject to accidental 
 variations, being stopped here or there arbitrarily by the 
 action of the antagonistic muscles, as was shown by graphic 
 curves of the movement. The angle of movement made in 
 nearly all of these experiments was 20°. The electric contact 
 being broken when the lever was moved away from the 
 metal post, it was closed again when it passed over the twenty- 
 degree mark, by a specially devised contact apparatus. About 
 6 cm. from the end of the lever a clamp held a rather stiff steel 
 wire, which passed downward about 15 mm. and then bending 
 at a right angle extended as far as the edge of the wooden base. 
 This piece of flexible wire served to close a contact apparatus 
 or key, situated on the edge of the wooden base about twenty 
 degrees from the metal post. Several different keys were tried. 
 That finally adopted consisted of a semicircle of thin sheet 
 brass filed down at the ends and pivoted at the center of the 
 circle. The single radius passed upward from the pivot to the 
 semicircle and was thence continued about 2 cm. This up- 
 ward projection was covered by a piece of soft rubber tubing, 
 which served as insulation and also to deaden the sound. When 
 the piece of steel wire struck the rubber it threw this semicir- 
 cular piece of brass over until it was clasped by two jaws of 
 spring-brass, an electric contact being thereby established and 
 a record made of the end of the movement. Both this contact 
 and that at the post were on the same circuit as an electromag- 
 netic sound-hammer which gave the signal for reaction. The 
 hammer was operated, of course, independently of this circuit 
 and served both to give the preparatory signal and the stimu- 
 lus for reaction. On breaking the sound-hammer circuit, the 
 electromagnet was demagnetized, the hammer was pulled up 
 by a spring and struck a bell above. This gave the warning 
 signal. On closing this circuit again the hammer was drawn 
 and struck a metal anvil. This stroke closed the same circuit 
 in which the lever, above described, was connected. The sound 
 served as a signal to react. The closing of the circuit was re- 
 corded in another room by an electromagnetic time-marker, 
 
REACTION TIME AND a MOVEMENT. 15 
 
 which wrote on a smoked drum and gave five hundred double 
 vibrations a second. When this same circuit was broken by 
 the outward movement of the arm, and closed again as the 
 lever passed the twenty-degree mark, both the breaking and 
 the making of the circuit were again recorded by the electro- 
 magnetic time-marker in the distant room. The giving of pre- 
 paratory signal and the sound stimulus for reaction was done 
 mechanically by a slight modification of the older form of ap- 
 paratus which Wundt called the time-sense apparatus, and de- 
 scribed in the fourth edition of his ' Grundziige der physiologi- 
 schen Psychologic ' x One of the contact-breakers there described 
 served to break the current, thus giving the preparatory signal. 
 A metal bar was placed on another one of these contrivances, 
 and when the steel projection on the wheel of the apparatus 
 reached this bar, contact was established and the rotation of the 
 apparatus stopped. A special series of experiments was made 
 by which this instrument was calibrated so as to measure, quite 
 accurately, intervals of one-half second. The interval between 
 the preparatory signal and the stimulus for reaction could then 
 be varied at will, by placing the contact-breaker at the proper 
 number of degrees from the metal bar. 
 
 A single pole switch was connected with the wires running 
 to the contact-breaker so that the circuit could be closed by it, 
 and the wheel moved back to a definite starting point without 
 again breaking the circuit and confusing the signals in the 
 reacting-room. A diagram of the connections is given below. 
 The drum used to take the records was turned by hand. The 
 axis of this drum was an endless screw, by means of which it 
 was moved backwards or forwards about 3 mm. at each revo- 
 lution. The tuning-fork and time-marker were clamped on 
 stands which, after being properly adjusted, were screwed 
 down to a wooden platform. This platform was supported at 
 two corners by metal rods to which it was pivoted. Two metal 
 rings, connected eccentrically by an axis, supported the other 
 two corners. Turning a handle on one end of this axis raised 
 or lowered the platform, thus raising the time-marker and 
 tuning-fork from the smoked drum, or lowering them upon it 
 
 1 Vol. II., p. 422. 
 
i6 
 
 THOMAS V. MOORE. 
 
 till the proper pressure was exerted to secure a continuous 
 record. After some practice the experimenter was able to take 
 about forty records on the drum, which was 14 cm. long and 
 16.7 cm. in diameter. 
 
 The subjects who took part in these experiments were Dr. 
 Pace and several students of the university. Only after a set 
 of experiments was completed were the results made known to 
 the subjects. And though in certain cases the experimenter 
 expected the results obtained, his surmises were not communi- 
 cated to the subjects beforehand. This, of course, is a very 
 important precaution in psychological experiments, for a biased 
 mental attitude of the subject is very likely to affect the results 
 
 Fig. I. A, time sense apparatus; a, bar contact maker; b, contact 
 breaker ; c, one pole switch ; B, recording drum ; C, electromagnetic marker ; 
 D t tuning fork ; E, electromagnetic sound hammer ; F, bell ; G, wooden base 
 for lever ; H, lever ; d, arm-rest ; e, starting past first contact apparatus ; / 
 ond contact apparatus ; / II III, batteries. 
 
 obtained. Unless otherwise mentioned, the subjects had made 
 several practice-series before the results recorded below were 
 obtained. The principal subjects in these experiments were 
 Dr. Pace (A), Mr. McMullen (B) t Mr. Fagan (Q, and Mr. 
 Mullaly (&). These subjects will hereafter be referred to by 
 the letters in parentheses after their names. Other subjects 
 who made but a few experiments will be referred to by arabic 
 numerals. 
 
V. EXPERIMENTAL RESULTS. 
 
 i. Relation between Reaction Time and the Speed 
 
 of Subsequent Movement when the Subject is 
 
 not Instructed to make a Rapid Movement. 
 
 The few experiments here recorded bear upon the same 
 problem which was undertaken by Professor Delabarre and his 
 associates. Though not the first experiments in the order of 
 time, they are given the first place in this dissertation because 
 they have the nature of a preliminary study rather than an 
 integral part of the problem under discussion. The purpose of 
 this set of experiments was to determine whether or not any 
 relation might exist between the variations in reaction time and 
 the different speeds of movement with which each reaction 
 might happen to be made. While there seemed to be no reason 
 to doubt Professor Delabarre's conclusion, or to expect that the 
 speed of movement would reveal a relation which a study of the 
 force of movement failed to detect, still it was thought best to 
 see if a new method and different apparatus would confirm pre- 
 vious results. 
 
 The subjects chosen for these experiments were totally 
 unfamiliar with the work, and knew nothing of the experi- 
 ments in which the subjects had been told to react with the 
 quickest possible movement. The reason for the choice of 
 such men was to secure a perfectly spontaneous movement. 
 Subjects previously practiced in the quickest possible move- 
 ment would have found it hard to react with a movement uninflu- 
 enced by their previous training. The subjects chosen had 
 never practiced reaction at all ; but this was by no means a 
 necessary qualification for the present experiment. For if, by 
 any possibility, a slow movement were the invariable result of 
 a slow reaction and a quick movement of a quick reaction, or 
 vice versa, it would not make any difference whether the sub- 
 ject had previously practiced reaction or not. Practice would 
 merely lessen both variations. 
 
 (17) 
 
1 8 THOMAS V. MOORE. 
 
 The subjects were instructed to respond to the signal for 
 reaction by moving outward the lever above described as soon 
 as they could. Nothing was said to them about making a rapid 
 movement, or taking care to pass the twenty-degree line ; but it 
 was found that the natural movement was always greater than 
 twenty degrees. The results are tabulated below. In these 
 and the following tables time is expressed in thousandths of a 
 second (<r) under the tables headed Reaction, Movement, and 
 M. V., which signify respectively reaction time, movement 
 time, and mean variation. In the column headed No. the 
 number of experiments is given. It may be stated here, once 
 for all, that by reaction time I mean the process usually so 
 designated. By movement time, or speed of movement, I mean 
 the time elapsing during a certain part of the movement by 
 which the reaction is executed. The close of the reaction time 
 marks the beginning of the movement time, which is itself com- 
 pleted when the arm passes through the angle agreed upon. 
 Unless otherwise noted the angle in all of the subsequent 
 experiments is one of twenty degrees ; the preparatory signal 
 was given two seconds before the tap of the hammer which 
 served as a stimulus for reaction. 
 
 Subject i. 
 Series I. Angle of Movement 20°. 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M V. 
 
 No 
 
 186 
 
 22 
 
 IO 117 
 
 IO 
 
 IO 
 
 
 Series II. 
 
 Angle of Movement 
 
 12°. 
 
 
 Reaction. 
 
 M. v. 
 
 No. Movement. 
 
 M V 
 
 No. 
 
 158 
 
 36 
 
 13 140 
 
 Subject 2. 
 
 20 
 
 13 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M v. 
 
 No. 
 
 170 
 
 33 
 
 II 1S9 
 
 23 
 
 12 
 
 These tables show that, while the variation in movement 
 time under the conditions of these experiments is less than in the 
 reaction time, still it may be considerable. In order to bring 
 out clearly how the two times vary, curves have been plotted 
 which represent the variations in five-hundredths of a second. 
 The continuous lines represent the reaction time, the dotted ones 
 the movement time. The figures along the axis of . 
 
REACTION TIME AND MOVEMENT. 
 
 19 
 
 refer to the number of the experiment in each series ; those 
 along the axis of ordinates to time in five-hundredths of a sec- 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 k / 
 
 
 
 
 
 
 
 
 \ jy 1 
 
 \ / 
 
 l\ 
 
 /\ 
 
 / 
 / 
 
 / 
 
 X 
 
 / t 
 
 \ 
 
 
 
 
 \ / 
 
 / > 
 
 \ 
 
 / \ 
 
 ' \ 
 
 / 
 
 
 // 
 
 \ 
 \ 
 \ 
 
 X, 
 
 y 
 
 v. v 
 
 A 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 ' i 
 
 J 
 
 
 
 •i 
 
 4 
 
 1 
 
 « 
 
 « 
 
 / 
 
 
 
 
 Fig. 2. 
 
 *■• 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 90 
 
 \ 
 
 \ 
 \ 
 
 * ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 y 
 
 v 
 
 • 
 
 s. 
 
 fy 
 
 ,^' 
 
 \ 
 
 / 
 
 
 
 
 \ 
 
 s 
 
 \ 
 
 / 
 
 
 
 
 \ 
 \ 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • Z » « kT * 7 */••"/» 
 
 Fig. 3. 
 
 ond. Here and elsewhere a break in a curve indicates an un- 
 recorded reaction time or movement time. 
 
20 
 
 THOMAS V. MOORE. 
 
 From these curves it is evident that the time of reaction may 
 increase concomitantly with the movement time, or the reverse 
 may take place. One may increase or decrease considerably 
 while the other is but slightly changed. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 *v 
 
 
 
 
 
 
 / 
 
 \ 
 
 / 
 
 
 
 
 \ 
 
 
 
 
 
 
 s 
 
 / 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 / 
 
 r 
 
 
 
 
 
 
 
 
 
 } 
 
 
 / 
 
 
 
 
 s 
 
 
 
 
 S?' 
 
 
 \ 
 
 T 
 
 \ 
 
 * 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Fig. 4. 
 
 2. Relation Between Reaction Time and Movement 
 
 Time When the Subject is Told to Respond to 
 
 the Stimulus With the Quickest 
 
 Possible Movement. 
 
 The experiments given under this heading bear upon the 
 
 fundamental problem of the dissertation. What relation, if anv, 
 
 exists between reaction time and its movement time, when the 
 
 subject is not only instructed to respond to the stimulus as soon 
 
 as possible, but also by the most rapid movement of which he 
 
 is capable? Sufficient has already been said about this problem 
 
 to bring out the purpose of the experiments given below. But 
 
 it should be noted that the mental attitude of the subject is not 
 
 the same as in an ordinary simple reaction. There is another 
 
 factor present in the preparation for the reaction. Not only is 
 
 the idea of starting as soon as possible in the subject's mind, 
 
 but there is also an additional motor representation. He must 
 
REACTION TIME AND MOVEMENT. 21 
 
 make the fastest movement of which he is capable. The two 
 ideas, however, do not seem to be antagonistic. They har- 
 
 SUBJECT A. 
 
 /. Series in which the Preparatory Signal was 4%. Seconds. 
 
 action. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 167 
 
 12 
 
 6 
 
 Il8 
 
 4 
 
 6 
 
 165 
 
 27 
 
 9 
 
 Il6 
 
 10 
 
 9 
 
 155 
 
 13 
 
 10 
 
 115 
 
 5 
 
 10 
 
 137 
 
 27 
 
 7 
 
 113 
 
 4 
 
 7 
 
 122 
 
 II 
 
 9 
 
 I20 
 
 7 
 
 9 
 
 156 
 
 54 
 
 7 
 
 136 
 
 9 
 
 7 
 
 137 
 
 21 
 
 13 
 
 103 
 
 6 
 
 13 
 
 144 
 
 23 
 
 11 
 
 121 
 
 6 
 
 11 
 
 155 
 
 29 
 
 9 
 
 122 
 
 5 
 
 9 
 
 143 
 
 16 
 
 13 
 
 IOI 
 
 3 
 
 13 
 
 monize so well that one does not feel that much more additional 
 effort is required to react with the quickest possible movement 
 
 II. Series in which the Preparatory Signal was 2 Seconds. 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 147 
 
 7 
 
 IO 
 
 108 
 
 7 
 
 II 
 
 141 
 
 19 
 
 IO 
 
 107 
 
 4 
 
 IO 
 
 151 
 
 13 
 
 8 
 
 I07 
 
 5 
 
 IO 
 
 157 
 
 16 
 
 IO 
 
 114 
 
 7 
 
 IO 
 
 164 
 
 18 
 
 13 
 
 I20 
 
 5 
 
 14 
 
 143 
 
 12 
 
 14 
 
 112 
 
 5 
 
 14 
 
 168 
 
 20 
 
 12 
 
 no 
 
 6 
 
 13 
 
 160 
 
 14 
 
 12 
 
 III 
 
 4 
 
 12 
 
 156 
 
 II 
 
 II 
 
 I06 
 
 4 
 
 12 
 
 166 
 
 27 
 
 9 
 
 115 
 
 5 
 
 9 
 
 159 
 
 14 
 
 II 
 
 112 
 
 4 
 
 IO 
 
 175 
 
 6 
 
 IO 
 
 II 9 
 
 5 
 
 12 
 
 180 
 
 27 
 
 IO 
 
 Il6 
 
 5 
 
 IO 
 
 140 
 
 26 
 
 8 
 
 no 
 
 5 
 
 II 
 
 137 
 
 22 
 
 11 
 
 "3 
 
 5 
 
 14 
 
 123 
 
 14 
 
 IO 
 
 no 
 
 3 
 
 IO 
 
 159 
 
 18 
 
 IO 
 
 112 
 
 4 
 
 II 
 
 129 
 
 16 
 
 9 
 
 104 
 
 2 
 
 IO 
 
 163 
 
 26 
 
 11 
 
 102 
 
 5 
 
 13 
 
 than if the movement were left undetermined by any previous 
 instruction. 
 
 The results obtained from this line of work are here given. 
 
22 THOMAS V. MOORE. 
 
 
 Subject 
 
 B. 
 
 
 
 I. 
 
 Series in which the Preparatory Signal was 4 X / Z Seconds. 
 
 
 Reaction. 
 
 M. V. No. 
 
 Movement. 
 
 M. V. 
 
 No 
 
 109 
 
 8 9 
 
 IOO 
 
 6 
 
 9 
 
 109 
 
 12 8 
 
 IOO 
 
 4 
 
 8 
 
 117 
 
 9 8 
 
 99 
 
 6 
 
 8 
 
 147 
 
 22 7 
 
 92 
 
 6 
 
 8 
 
 136 
 
 15 16 
 
 102 
 
 1 
 
 16 
 
 142 
 
 17 10 
 
 IOI 
 
 4 
 
 10 
 
 143 
 
 13 10 
 
 98 
 
 2 
 
 10 
 
 152 
 
 19 10 
 
 96 
 
 3 
 
 10 
 
 133 
 
 11 9 
 
 92 
 
 3 
 
 9 
 
 148 
 
 22 9 
 
 IOO 
 
 3 
 
 9 
 
 166 
 
 31 12 
 
 94 
 
 5 
 
 12 
 
 133 
 
 12 10 
 
 96 
 
 3 
 
 10 
 
 l6l 
 
 46 12 
 
 9i 
 
 3 
 
 12 
 
 136 
 
 12 10 
 
 95 
 
 3 
 
 10 
 
 141 
 
 19 12 
 
 94 
 
 3 
 
 12 
 
 II. Series in which the Preparatory Signal was 2 Seconds. 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 145 
 
 16 
 
 13 
 
 S4 
 
 6 
 
 13 
 
 151 
 
 18 
 
 13 
 
 83 
 
 4 
 
 13 
 
 147 
 
 14 
 
 II 
 
 98 
 
 5 
 
 12 
 
 155 
 
 II 
 
 12 
 
 90 
 
 4 
 
 13 
 
 165 
 
 II 
 
 II 
 
 S6 
 
 3 
 
 II 
 
 155 
 
 15 
 
 13 
 
 77 
 
 3 
 
 13 
 
 171 
 
 14 
 
 12 
 
 87 
 
 3 
 
 13 
 
 158 
 
 39 
 
 8 
 
 S9 
 
 3 
 
 8 
 
 164 
 
 30 
 
 9 
 
 93 
 
 3 
 
 8 
 
 113 
 
 26 
 
 13 
 
 95 
 
 4 
 
 13 
 
 168 
 
 22 
 
 26 
 
 86 
 
 5 
 
 36 
 
 ISO 
 
 10 
 
 10 
 
 S5 
 
 6 
 
 10 
 
 148 
 
 35 
 
 S 
 
 S5 
 
 4 
 
 
 148 
 
 11 
 
 H 
 
 90 
 
 2 
 
 14 
 
 134 
 
 12 
 
 14 
 
 97 
 
 2 
 
 12 
 
 109 
 
 8 
 
 12 
 
 103 
 
 3 
 
 12 
 
 166 
 
 32 
 
 8 
 
 S5 
 
 4 
 
 8 
 
 156 
 
 11 
 
 10 
 
 88 
 
 6 
 
 10 
 
 158 
 
 20 
 
 16 
 
 81 
 
 4 
 
 
 I30 
 
 14 
 
 10 
 
 95 
 
 3 
 
 11 
 
 H3 
 
 16 
 
 11 
 
 94 
 
 4 
 
 11 
 
 104 
 
 9 
 
 10 
 
 102 
 
 1 
 
 " 
 
 114 
 
 10 
 
 12 
 
 96 
 
 3 
 
 12 
 
 123 
 
 7 
 
 11 
 
 98 
 
 4 
 
 11 
 
 141 
 
 16 
 
 11 
 
 93 
 
 3 
 
 11 
 
 158 
 
 16 
 
 12 
 
 95 
 
 5 
 
 13 
 
REACTION TIME AND MOVEMENT. 
 
 2 3 
 
 Subject C. 
 Preparatory Signal 2 Seconds. 
 
 Reaction. 
 103 
 134 
 145 
 151 
 156 
 142 
 
 M. V. 
 II 
 29 
 
 8 
 14 
 17 
 14 
 
 No. 
 IO 
 IO 
 
 13 
 12 
 
 13 
 13 
 
 Movement. 
 I02 
 
 97 
 104 
 I02 
 117 
 107 
 
 M. V. 
 I 
 
 3 
 6 
 
 3 
 
 7 
 4 
 
 Reaction 
 162 
 
 159 
 162 
 146 
 
 Subject D. 
 /. Series in which the Preparatory Signal was 4% Seconds. 
 
 Movement. M. V. 
 
 119 4 
 
 121 6 
 
 M. V. 
 25 
 22 
 40 
 IO 
 
 No. 
 II 
 IO 
 
 13 
 IO 
 
 112 
 Il8 
 
 II. Series in which the Preparatary Signal was 2 Seconds. 
 
 Reaction. M. V. No. Movement. M.V. 
 
 191 26 12 97 6 
 
 170 16 13 93 7 
 
 I48 16 12 I04 5 
 
 164 27 12 II3 4 
 
 No. 
 II 
 II 
 
 13 
 12 
 
 13 
 13 
 
 No. 
 12 
 12 
 
 13 
 II 
 
 No. 
 13 
 13 
 12 
 12 
 
 In examining the results obtained in these tables the follow- 
 ing points are at once evident. The reaction times are usually 
 somewhat longer than muscular reactions made with a tele- 
 graph-key to sound stimuli. The mean variations of the reac- 
 tion times are also longer than those generally found in muscu- 
 lar reactions. The mean variation of the movement time is 
 about five thousandths of a second. Subject D had the most 
 variable movement time ; but the results recorded under head- 
 ing (I.) for this subject were the first taken from him; and the 
 series given in the second division were taken at rather long 
 intervals of time. The subject was not trained to the work. 
 Notwithstanding this fact, the time of movement varies but little 
 — less indeed than the time of ordinary muscular reactions. 
 
 The fact that the subjects were told to make the quickest pos- 
 sible movement required attention to the movement — the condi- 
 tion most favorable for a muscular reaction. Previous to reac- 
 tion there was noticed a tension of the muscles, which seemed 
 to show that the strain of attention was directed to the efferent 
 and not to the afferent side of the process. Occasional errone- 
 
24 THOMAS V. MOORE. 
 
 ous reactions (e. g., to the preparatory signal) and previous re- 
 actions were also noticed. From these facts it seems most 
 probable that the reactions here recorded are what the Wundt- 
 ian school would consider muscular. The variation from the 
 usual time of muscular reaction and the larger mean variation 
 may be accounted for on two grounds. In the first place, as 
 Cattell has found, the reaction time for the shoulder is longer 
 than that for wrist and finger, which have usually been em- 
 ployed in experiments on reaction time. In the second place, 
 no attempt has been made to secure uniformity by excluding 
 figures which were considerably above the mean value of a 
 series. Only the most exceptionally long (e. g., 400 a) or short 
 reactions (e. g:, 50 a) have been omitted. And it scarcely need 
 be said that the same rule was applied to the movement time. 
 These very exceptional values, however, occurred but seldom 
 for reaction time, and almost never in the records of the move- 
 ment. The reason for this method of procedure is, of course, 
 apparent. A relation was sought between the variations in re- 
 action time and those which might exist in the movement time. 
 Hence, only the most exceptional variations in reaction time 
 should be excluded. And it may be appropriate to state here 
 that I cannot wholly agree with Cattell when he says, " Owing, 
 however, to the reflex nature of the reaction, its length is not 
 greatly affected by the condition of the observer, the time of day, 
 the number of reactions already made, nor the amount of prac- 
 tice.*' 1 I have found quite a difference in the mean value of reac- 
 tion time on different days ; and it would be hard to explain this 
 except on the supposition of variations in the condition of the 
 subject. With subject C I am quite certain that anything ap- 
 proaching regularity was only attained after considerable prac- 
 tice. With other subjects I have found that the very first series 
 taken from them was very constant and apparently of the mus- 
 cular form. The statement that reaction time is not greatly af- 
 fected by the amount of practice seems to indicate a change in 
 the author's position since 1886. He then wrote: "When a 
 subject has had no practice in making reactions (in which case 
 
 1 'On Reaction Times and Velocity of the Nervous Impulse, ' Xat. Acad. 
 of Sciences, Vol. VII., p. 394. 
 
REACTION TIME AND MOVEMENT. 
 
 25 
 
 the reaction time is usually longer than 150 a) I think the will- 
 time precedes the reaction." 1 
 
 Just what position is taken in this paper on the distinction 
 between muscular and sensorial reactions, and the theory of 
 types, will best be mentioned in the theoretical discussion of 
 the results. For the present it will suffice to recognize pro- 
 visionally Lange's distinction between muscular and sensorial 
 reactions. 
 
 The empirical conclusion that the set of experiments war- 
 rants is this : When a subject is told to react with the quickest 
 possible movement, the reaction time may be subject to consider- 
 
 190 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1» 
 
 
 
 
 
 
 
 / 
 
 \ 
 
 
 
 
 
 
 1 
 
 \ 
 
 
 / 
 
 S^ 
 
 
 
 
 / 
 
 
 \ 
 
 
 
 
 
 
 / 
 
 \ 
 
 
 / 
 
 s 
 
 ■^ 
 
 ^ 
 
 \ 
 
 / 
 
 
 
 
 
 
 
 / 
 
 f 
 
 
 
 
 
 
 
 \ 
 
 f 
 
 
 ^ 
 
 — < 
 
 ^ 
 
 *^»- 
 
 ■*•*«*, 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 JO 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Fig. 5. 
 
 able variation, but the movement time remains fairly constant. 
 
 To bring out the relation between the individual experiments 
 
 of the series, curves similar to those given above have been 
 
 plotted out. The continuous lines represent reaction time, the 
 
 dotted ones the movement time. The figures along the axis of 
 
 abscissas refer to the number of the experiment in the series ; 
 
 those along the axis of ordinates to time in five-hundredths of 
 
 a second. 
 
 1 Philosophische Studien, Vol. III., p. 322. Also in Mind, 1886, Vol. XI., 
 p. 232. 
 
26 
 
 THOMAS V. MOORE. 
 
 lit 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 >Zo 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ioc 
 
 
 
 
 
 
 
 
 
 
 
 j 
 
 
 
 
 Vtf 
 
 
 
 
 
 
 
 
 ) 
 
 \ 
 
 
 / 
 
 \ 
 
 
 
 He 
 
 
 
 
 
 
 
 
 I 
 
 V 
 
 l\ 
 
 / 
 
 \ 
 
 
 
 it 
 
 Co 
 
 
 
 
 
 
 
 
 
 
 s 
 
 f 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 .... 
 
 • ^ 
 
 
 -''' 
 
 
 
 ^ 
 
 
 
 
 y 
 
 _ 
 
 .— 
 
 
 3c 
 
 
 
 
 
 
 
 " 
 
 1 
 
 — 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Fig. 6. 
 
 
 j j * j- « y $ * *r •> '* '■> *+ 
 
REACTION TIME AND MOVEMENT. 27 
 
 From these curves it is at once evident that the line for reac- 
 tion is subject to considerably more irregularity than the one for 
 movement. The curves also bring out more than the tabulated 
 results of mean values. For if there were a constant ratio be- 
 tween the slight variations in the movement time and the large 
 differences in the reaction times, it would not appear in the table 
 of mean values. But when we look at these curves it can 
 easily be seen that no such relation exists. A reaction which is 
 longer than the average is sometimes followed by a movement 
 whose value is less than the mean. And then, again, the 
 reverse may take place or both may vary in the same direction. 
 So that it is clearly impossible to state that any direct or inverse 
 ratio exists between the two times. 
 
 3. Record of Reaction with Lever, but without In- 
 tentional Regard to the Speed of the Subse- 
 quent Movement, from a Subject Previ- 
 ously Practiced in Making the 
 Movement as Quick as 
 Possible. 
 As we said in introducing the last set of experiments, the 
 mental conditions under which they were made varied some- 
 what from the normal state of preparation for simple reactions. 
 The mental state was more complex. There was an added 
 element in the motor preparation for the reaction. The subject 
 had not only to prepare to move as soon as possible, but also in 
 moving to do so as fast as he could. The added element in 
 the motor preparation for the movement required, as we said, 
 a certain amount of attention to the movement, occasioning 
 thereby a tendency towards muscular reaction. Does this more 
 complex mental attitude in any way affect the time of reaction 
 or not ? Will the two ideas so harmonize as to leave the time 
 of reaction unchanged ? Or, if the subject is not instructed to 
 make a rapid movement, will this simplification of the motor 
 preparation make it easier for him to react sooner and thereby 
 shorten the reaction ? Or will the removal of the idea of mak- 
 ing a fast movement make less likely the focusing of the atten- 
 tion on efferent processes, thereby allowing scope for the sen- 
 sorial form of reaction and lengthening the mean time ? 
 
28 THOMAS V. MOORE. 
 
 \ Experiments were made on Subject A, in order to throw 
 some light on these questions. Ten series were taken, giving 
 in all a hundred and nineteen experiments. This subject was 
 instructed to react as soon as he could on hearing the proper 
 signal, but to take no care of the subsequent movement whether 
 it was fast or slow. To help towards an indifferent state of 
 mind in regard to the movement the contact apparatus was 
 removed from its position on the wooden base of the apparatus. 
 This subject's previous experiments had been made with an 
 interval of four and a half seconds between the preparatory 
 signal and the stimulus for reaction. The same interval was 
 allowed in the following experiments. The first three series 
 were taken consecutively on December 12, and the rest were 
 made consecutively five days later. No other experiments were 
 made with this subject between these two sets of experiments. 
 Before commencing the first set it had been one day since he 
 had made any experiments at all. These intervals allowed to 
 some extent the previous idea of reacting with a rapid move- 
 ment to die away. 
 
 Subject A. 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 144 
 
 18 
 
 II 
 
 129 
 
 18 
 
 12 
 
 141 
 
 19 
 
 12 
 
 155 
 
 30 
 
 13 
 
 l6l 
 
 17 
 
 II 
 
 131 
 
 19 
 
 12 
 
 139 
 
 18 
 
 II 
 
 133 
 
 14 
 
 II 
 
 140 
 
 18 
 
 12 
 
 132 
 
 iS 
 
 13 
 
 In comparing these results with those of the same subject 
 when he attempted to react with the quickest possible move- 
 ment (preparatory signal four and a half seconds) l we find that 
 in general the reaction time in the series just reported is some- 
 what quicker and the mean variation less than in the former 
 series. At first sight it would seem that these results are against 
 our former statement that attention to making the movement as 
 quickly as possible gave a tendency to react in a muscular 
 manner. But this is not the case, as will appear on a little 
 closer analysis. Subject A (Dr. Pace) had practised reaction 
 before taking up this series of experiments. His reactions in 
 those experiments were of the sensory type. When commenc- 
 
 1 Supra, p. 21. 
 
REACTION TIME AND MOVEMENT. 29 
 
 ing to act as subject in these experiments his first practice series 
 were generally of the longer form with occasional shorter and 
 apparently muscular reactions. Under the influence, as it 
 would appear, of the idea of making the movement as quick as 
 possible, his reactions soon became quicker until they were of 
 the length already tabulated. They have never been, except 
 in a few series, of the extreme muscular form. When, how- 
 ever, he was told in the series just reported to react without re- 
 gard for the movement, the influence of his late practice was 
 still felt and the tendency to muscular reaction remained. But, 
 while it seems that direction of the attention towards the attain- 
 ment of speed in the movement of reaction gives a tendency 
 towards a muscular reaction, still it must be admitted that the 
 more complex mental state may be something of a hindrance — 
 at least with this subject. It is a well-known fact that thinking 
 of how we are to perform an action makes us clumsy. A men- 
 tal representation of a movement is not the most favorable con- 
 dition for its execution. But a ?nental representation of a move- 
 ment and the muscular tension in preparation for the movement 
 are two very different things. It is the muscular tension which 
 makes the favorable condition for a muscular reaction, not the 
 mental picture. In reacting, therefore, with the quickest pos- 
 sible movement there are two factors to be taken into consider- 
 ation. One is the muscular tension which prepares us for a 
 sudden movement and indicates that the attention is strained 
 upon the efferent processes. The other is the mental picture of 
 moving the arm rapidly through the angle agreed upon. The 
 muscular tension gives the tendency towards the quicker form 
 of reaction, the mental picture tends to interfere with a quick 
 reaction. The necessity of making a rapid movement developed 
 this condition of tension, and led subject A to drop his previous 
 sensorial form of reaction. The idea in his mind of making a 
 rapid movement tended to interfere with the start of the move- 
 ment, for when this idea was put out of mind the reaction time 
 quickened and the mean variation was lessened. It is to be re- 
 gretted that more time was not at hand to go further into the 
 question of practice in relation to our experiments than we have 
 done. The experiments to be reported in the next section bear 
 
30 THOMAS V. MOORE. 
 
 more upon the attainment of constancy in the speed of move- 
 ment than the effect of practice on reaction time. 
 
 4. The Effect of Practice on Movement Time. 
 
 A full study of the influence of practice on reaction time 
 and movement time should be the object of a special piece of 
 research rather than a part of our present investigation. Several 
 subjects should be practised in the ordinary form of reaction 
 with a telegraph key. They should be practiced in reacting 
 with the lever without care for the speed of the subsequent 
 movement. The effect of directing the attention to stimulus or 
 muscle should be ascertained. And if subjects were found who 
 could react only in the sensorial manner, these especially should 
 be practised in reacting with the quickest possible movement. 
 The results obtained might throw some new light on the dis- 
 cussion between the Wundtian school and the supporters of 
 Professor Baldwin and his theory of types. But such an inves- 
 tigation would be beyond the limits of the present study. The 
 question of practice probably would not have been mentioned 
 at all had it not been noticed that fair constancy in the speed of 
 movement was obtained almost from the very start with all our 
 subjects but one. 
 
 To see with what constancy of movement subjects might 
 react who had no practice at all, several students were asked 
 to take part in the experiments who had not previously been 
 employed for this line of work. They were instructed to react 
 as quickly as they could on hearing the proper signal, and move 
 the lever through the angle of twenty degrees as fast as they 
 could. A few unrecorded trials were made to familiarize them 
 with the signals and then the following series were taken. 
 
 
 Reaction. 
 
 M. V. 
 
 No 
 
 Movement. 
 
 M V. 
 
 No 
 
 Subject (3) 
 
 135 
 
 20 
 
 IO 
 
 106 
 
 3 
 
 IO 
 
 Subject (4) 
 
 106 
 
 9 
 
 II 
 
 I09 
 
 3 
 
 II 
 
 Subject (5) 
 
 151 
 
 15 
 
 5 
 
 1^7 
 
 4 
 
 5 
 
 Subject (6) 
 
 165 
 
 3i 
 
 10 
 
 
 3 
 
 10 
 
 (Subjects (5) and (6) had made a few trial experiments about two months 
 previously.) 
 
 With one of these subjects the mean variation in reaction 
 time was nine thousandths of a second, that in movement time 
 
REACTION TIME AND MOVEMENT. 3 1 
 
 three thousandths. This was the very first series of reactions 
 he had ever made. No doubt further practice would only show 
 that the general statement of Cattell's criticised above x holds 
 good for this subject. With all these subjects the constancy in 
 the movement time was attained without previous practice. 
 This is quite likely to be generally true in regard to movement 
 time ; but there are a number of normal subjects who do not 
 react constantly except after practice and some never attain to 
 constancy at all. 2 
 
 5. Effect of Varying the Preparatory Signal in 
 Successive Series. 
 
 In previous, experiments we have been mainly concerned 
 with the relation between reaction time and movement time under 
 what we may consider as normal conditions. If not absolutely 
 normal, they are normal relative to the present research. We 
 have already stated why it was decided to investigate the rela- 
 tion between reaction time and its speed of movement, made as 
 fast as possible. And that relation being the basis of the work, 
 it will serve as a form of comparison for reactions and move- 
 ments made under the influence of various other conditions. A 
 number of factors have been studied out and are known to in- 
 fluence reaction time to a greater or less extent. It will now 
 be our object to study the influence which these factors may 
 have on both the time of reaction and the speed of movement. 
 The interest which accrues from the study of this problem arises 
 from the fact that some light may be thrown upon the question 
 of just what processes of reaction time these disturbing factors 
 affect. Will those factors which affect reaction time have the 
 same or a different or no effect at all on the movement time? 
 
 The study was commenced with those factors which have 
 been supposed to affect reaction time by their influence on the 
 attention. It has long been known that the interval between 
 the preparatory signal and the stimulus for reaction affects the 
 time of reaction. 3 In order to test what effect this interval 
 
 1 Supra, p. 24. 
 
 2 Cf. E. B. Titchener, Mind, 1895, N. S., Vol. IV., p. 506-7. 
 
 3 Dwelshauwers, Phil. Stud., VI., p. 217-249. Martius, Phil. Stud., VI., p. 
 199. ff. 
 
32 
 
 THOMAS V. MOORE. 
 
 might have on the movement, several series were taken consecu- 
 tively in which that interval was of different lengths. The re- 
 sults are given below. The dates are published for each series, 
 and when several series have the same date, they were taken 
 consecutively. The reason for taking these consecutive series 
 was that both the time of movement and the reaction time vary 
 somewhat from day to day. This variation must be eliminated 
 as far as possible if any true comparison is to be made. 
 
 Subject A. 
 /. Preparatory Signal One Second. 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 12/25 
 
 141 
 
 12 
 
 12 
 
 114 
 
 6 
 
 12 
 
 12/25 
 
 157 
 
 IO 
 
 IO 
 
 107 
 
 4 
 
 IO 
 
 12/25 
 
 153 
 
 15 
 
 IO 
 
 I05 
 
 2 
 
 12 
 
 12/25 
 
 169 
 
 '5 
 
 9 
 
 108 
 
 5 
 
 12 
 
 12/25 
 
 155 
 
 23 
 
 13 
 
 107 
 
 5 
 
 14 
 
 Serial Means, 
 
 155 
 
 15 
 
 
 108 
 
 4 
 
 
 
 II. 
 
 Preparatory Signal 
 
 Two Seconds. 
 
 
 
 
 Reaction. 
 
 If. v. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 12/25 
 
 147 
 
 7 
 
 IO 
 
 108 
 
 7 
 
 II 
 
 12/25 
 
 141 
 
 19 
 
 IO 
 
 107 
 
 4 
 
 IO 
 
 12/25 
 
 151 
 
 13 
 
 8 
 
 I07 
 
 5 
 
 IO 
 
 12/25 
 
 157 
 
 16 
 
 IO 
 
 114 
 
 7 
 
 IO 
 
 Serial Means, 
 
 149 
 
 14 
 
 Subject C. 
 
 109 
 
 6 
 
 
 
 I. 
 
 Preparatory Signal 
 
 One Second. 
 
 
 
 
 Reaction. 
 
 If. v. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 12/26 
 
 I50 
 
 12 
 
 12 
 
 I05 
 
 4 
 
 12 
 
 12/26 
 
 171 
 
 19 
 
 12 
 
 99 
 
 3 
 
 12 
 
 12/26 
 
 Il8 
 
 24 
 
 10 
 
 IOI 
 
 4 
 
 13 
 
 Serial Means, 
 
 146 
 
 18 
 
 
 102 
 
 4 
 
 
 
 II. 
 
 Preparatory Signal 
 
 Two Seconds. 
 
 
 
 
 Reaction. 
 
 M. v. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 12/26 
 
 ™3 
 
 11 
 
 IO 
 
 I02 
 
 I 
 
 II 
 
 12/26 
 
 134 
 
 29 
 
 10 
 
 97 
 
 3 
 
 II 
 
 12/29 
 
 144 
 
 8 
 
 13 
 
 104 
 
 6 
 
 13 
 
 12/29 
 
 151 
 
 14 
 
 12 
 
 I02 
 
 3 
 
 12 
 
 Serial Means, 
 
 133 
 
 16 
 
 
 IOI 
 
 3 
 
 
 
 III. 
 
 Preparatory Signal 
 
 Three Seconds. 
 
 
 
 
 Reaction. 
 
 If. v. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 12/26 
 
 152 
 
 17 
 
 9 
 
 106 
 
 5 
 
 II 
 
 12/26 
 
 157 
 
 20 
 
 10 
 
 97 
 
 3 
 
 12 
 
 12/29 
 
 144 
 
 8 
 
 13 
 
 100 
 
 3 
 
 13 
 
 12/29 
 
 140 
 
 10 
 
 11 
 
 99 
 
 4 
 
 13 
 
 Serial Means, 
 
 14S 
 
 14 
 
 
 IOI 
 
 4 
 
 
REACTION TIME AND MOVEMENT. 33 
 
 These results indicate that when the preparatory signal comes 
 two seconds before the reaction stimulus, the conditions are 
 slightly more favorable for reaction than when it comes at either 
 one or three seconds before. But a preparatory signal two 
 seconds beforehand does not seem to be any more favorable for 
 the execution of the movement than when it comes at one or 
 three seconds before the stimulus for reaction. 
 
 6. Series Taken With an Irregular or no Prepara- 
 tory Signal. 
 
 The difficulty under which the attention labors in preparing 
 for a reaction when the preparatory signal comes at one or three 
 seconds beforehand, is certainly slight if compared with the 
 strain of keeping in readiness for reaction when the warning 
 signal is given at irregular intervals or not at all. At the end 
 of such a series of experiments there is a feeling of relief which 
 is indicative of the strain under which the attention was labor- 
 ing. Previous investigators have found that the efforts of a 
 subject to keep his attention focused were not successful and 
 that the time of reaction was considerably lengthened. But 
 will this condition of mental strain have the same effect on the 
 movement time? In considering this problem we must remem- 
 ber that we are dealing not only with a disturbance of the atten- 
 tion, but also with a stimulus arising from the mental effort to 
 keep the attention focused. The disturbance we may consider 
 as negative, for the conditions are merely unfavorable to con- 
 centration of the attention. Nothing positive is done to distract 
 the subject. He endeavors to make up for the lack of a warn- 
 ing signal by increased efforts to focus his attention. What will 
 be the effect of this mental activity on the movement time? 
 
 Subject A. 
 Series I. Preparatory Signal 4 X / Z Seconds. 
 
 Reaction. M. V. No. Movement. M. V. No. 
 
 167 25 9 114 I 7 
 
 Series II. No Preparatory Signal. 
 
 Reaction. M. V. No. Movement. M. V. No. 
 
 286 76 7 107 4 7 
 
34 
 
 THOMAS V. MOORE. 
 
 Reaction. 
 141 
 
 Reaction. 
 2IO 
 
 Reaction. 
 172 
 
 Reaction. 
 148 
 
 Reaction. 
 134 
 
 Reaction. 
 178 
 
 Reaction. 
 196 
 
 Reaction. 
 158 
 
 Reaction. 
 209 
 
 Subject B. 
 Series I. Preparatory Signal 4%, Seconds. 
 
 M. V. No. Movement. M. V. 
 
 19 12 94 3 
 
 Series II. Preparatory Signal None. 
 
 M. V. No. Movement. M. V. 
 
 20 11 88 2 
 Series I. Preparatory Signal None. 
 
 M. v. No. Movement. M. V. 
 
 12 26 91 3 
 
 Series II. Preparatory Signal 2 Seconds. 
 
 M. V. No. Movement. M. V. 
 
 11 14 90 2 
 
 Series I. Preparatory Signal 2 Seconds. 
 
 M. V. No. Movement. M. V. 
 
 12 14 97 2 
 
 Series II. Preparatory Signal None. 
 
 M. V. No. Movement. M. V. 
 
 20 25 95 5 
 
 Series I. Preparatoiy Signal None. 
 M. V. No. Movement. M. V. 
 
 4i 19 75 4 
 
 Series II. Preparatory Signal 2 Seconds. 
 
 M. V. No. Movement. M. V. 
 
 20 16 So 4 
 
 Series III. Preparatory Signal None. 
 
 M. V. No. Movement. M. V. 
 
 29 40 79 12 
 
 No. 
 12 
 
 No. 
 II 
 
 No. 
 27 
 
 No 
 14 
 
 No. 
 12 
 
 NO. 
 23 
 
 No 
 21 
 
 No. 
 17 
 
 No. 
 41 
 
 Serial Means, 
 
 Subject D. 
 
 /. Preparatory Signal 4% Seconds. 
 
 Reaction. If. V. No. Movement. M. V 
 
 162 40 13 112 6 
 
 146 IO II IlS 4 
 
 154 25 115 5 
 
 II. Preparatory Signal Irregular, 1 Second to 1 Minute. 
 Reaction. M. V. No. Movement. M.V. 
 
 278 50 10 114 4 
 
 232 3S 9 IIO 6 
 
 272 54 8 113 3 
 
 Serial Means, 261 47 112 4 
 
 No. 
 13 
 II 
 
 No. 
 IO 
 
 9 
 8 
 
 In the results just tabulated we notice an evident lengthen- 
 ing of reaction time when no preparatory signal is given. The 
 mean variation for the reaction time without preparatory signal 
 was generally larger than that of the normal series. These 
 
REACTION TJME AND MOVEMENT. 35 
 
 results do not altogether agree with the position taken by Wundt. 
 Quoting the work of Dwelshauwers, he says: "When the 
 stimuli are given without preparatory signal, the greater or less 
 endeavor to strain the attention has its effect indeed upon the 
 length, not upon the regularity of the reaction. " l 
 
 As to the movement time, it is clear that it is not affected to 
 such an extent as the reaction time. And, furthermore, what- 
 ever effect there may be upon it is not in the same direction. 
 For in the series without preparatory signals the movement 
 times were somewhat quicker than in the normal series. This 
 quickening, however, was slight — less than one hundredth of 
 a second. And though it could scarcely be considered to prove 
 conclusively that the strain of attention acted as mental stimulus 
 which reinforced the movement, still it would be hard to account 
 for the acceleration of the movement time on any other ground. 
 
 7. Series Taken without Any Preparatory Signal and 
 While the Subject Was Adding. 
 
 The disturbance of the attention occasioned by omitting the 
 preparatory signal is, as we have seen, negative in its character. 
 It merely increases the difficulty of attending, without doing 
 anything positive to disturb the attention. It remains to be seen 
 what will be the effect of joining to the negative disturbance 
 one of a positive character. Will this double disturbance 
 lengthen the movement time, or interfere with its regularity ? 
 In order that the results may be more closely comparable with 
 the last, it will be best to have the disturbance of an intellectual 
 rather than a sensory kind. For, as we have seen, the increased 
 effort of the subject to strain his attention may have acted as a 
 mental stimulus to the movement. Is it true, as M. Fere thinks, 2 
 that mental activity will increase the immediate output of mus- 
 cular energy? 
 
 But here we are concerned with the effect of disturbances of 
 the attention on reaction time and movement time, rather than 
 
 1 'Grundziige der physiol. Psychol.,' 4th ed., Vol. II., p. 349. 
 
 2 ' Sensation et Mouvement,' Paris, 1887, p. 7. ' Note sur l'influence recip- 
 roque du travail physique et intellectuel, ' Journal de VAnatomieet de la Phy- 
 siologie, 1901, Vol. XXXVII, p. 625, ff. 
 
3 6 THOMAS V. MOORE. 
 
 the reinforcement of the movement by various stimuli. This 
 latter problem will be given special attention further on. But 
 the two questions have points in common, and in investigating 
 one it becomes necessary to consider the other. 
 
 A disturbance of the attention, which at the same time is of 
 an intellectual character, can be produced when the subject is 
 told to carry on a process of addition during a series of experi- 
 ments. Subject A was told to add seventeen to seventeen from 
 the beginning of the series of experiments to the end, and to 
 try at the same time to be ready to react at the tap of the ham- 
 mer. When asked afterwards what influence the process of 
 addition seemed to have, he replied that the attempt to add did 
 not seem to increase greatly the difficulty of keeping himself in 
 readiness to react. Subject B, however, found it very difficult 
 and disagreeable. 
 
 In the results reported below, consecutive series are grouped 
 together. In each group there is a normal series which is to 
 be compared with those affected by the departure from normal 
 conditions. 
 
 In all series the preparatory signal was given two seconds 
 before the tap of the hammer, unless otherwise noted. This 
 remark about the normal series applies not only to this section, 
 but also to all subsequent sets of experiments. 
 
 The series are tabulated in the order in which they were 
 taken. 
 
 
 
 Subject A. 
 
 
 
 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 I. 
 
 
 268 
 
 32 
 
 12 
 
 115 
 
 7 
 
 12 
 
 
 (Normal), 
 
 175 
 
 6 
 
 IO 
 
 119 
 
 5 
 
 12 
 
 II. 
 
 (Normal), 
 
 14S 
 
 20 
 
 12 
 
 126 
 
 6 
 
 12 
 
 
 
 24S 
 
 20 
 
 II 
 
 114 
 
 5 
 
 II 
 
 [II. 
 
 
 317 
 
 50 
 
 IO 
 
 119 
 
 5 
 
 IO 
 
 
 (Normal), 
 
 180 
 
 27 
 
 IO 
 
 Il6 
 
 5 
 
 IO 
 
 IV. 
 
 (Normal), 
 
 197 
 
 17 
 
 15 
 
 106 
 
 3 
 
 15 
 
 
 
 268 
 
 24 
 
 23 
 
 III 
 
 2 
 
 25 
 
 V. 
 
 (Normal), 
 
 164 
 
 16 
 
 13 
 
 114 
 
 4 
 
 13 
 
 
 
 254 
 
 -: 
 
 -4 
 
 117 
 
 
 
 
 
 Subject B. 
 
 
 
 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 I. 
 
 (Normal), 
 
 16S 
 
 22 
 
 26 
 
 S6 
 
 
 36 
 
 
 
 341 
 
 42 
 
 26 
 
 93 
 
 9 
 
 -■ 
 
 
 (Normal), 
 
 I50 
 
 IO 
 
 IO 
 
 
 6 
 
 IO 
 
REACTION TIME AND MOVEMENT. 
 
 37 
 
 
 
 366 
 
 54 
 
 10 
 
 106 
 
 11 
 
 9 
 
 II. 
 
 (Normal), 
 
 148 
 
 35 
 
 8 
 
 85 
 
 4 
 
 7 
 
 
 
 357 
 
 80 
 
 13 
 
 113 
 
 15 
 
 13 
 
 III. 
 
 
 298 
 
 65 
 
 10 
 
 98 
 
 4 
 
 14 
 
 
 (Normal), 
 
 166 
 
 32 
 
 8 
 
 85 
 
 4 
 
 8 
 
 
 
 265 
 
 35 
 
 10 
 
 104 
 
 8 
 
 16 
 
 IV. 
 
 
 279 
 
 23 
 
 10 
 
 102 
 
 10 
 
 10 
 
 
 (Normal), 
 
 156 
 
 11 
 
 10 
 
 88 
 
 6 
 
 10 
 
 
 
 282 
 
 43 
 
 13 
 
 105 
 
 12 
 
 13 
 
 «* 
 
 
 
 
 
 li 
 
 
 
 
 
 
 
 
 
 
 <b» 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 1 
 
 \ 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 / 
 
 \ 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 i 
 
 \ 
 
 
 
 \ 
 
 / 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 f 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -^ 
 
 ^ 
 
 
 
 » 
 
 
 ,-■- 
 
 \ 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 y 
 
 
 
 \ 
 
 — „ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Fig. 8. 
 
 From these results it is perfectly clear that subject B can- 
 not carry on a process of addition and react with as quick a 
 
38 
 
 THOMAS V. MOORE. 
 
 movement as he is capable of making under normal conditions. 
 But it is to be remembered that this subject found the process of 
 addition a disagreeable as well as a difficult task. With subject 
 A, who found the process but a slight source of distraction, the 
 lengthening of the movement time is not so great nor is it con- 
 stant. On two occasions his movement was quicker while 
 adding than under normal conditions. 
 
 '7. 
 /»» 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 *• 
 «. 
 
 *• 
 
 J". 
 *c 
 3, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 V 
 
 
 / 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^, 
 
 
 
 " 
 
 
 — -- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 /« 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 7 f 
 
 Fig. 9. 
 
 '4 ** " f 
 
 In the experiments in the previous section, where the condi- 
 tions were not favorable for concentrating the attention upon the 
 reaction and movement, it was certainly evident that the n 
 tion time was lengthened and that the movement time was not 
 retarded, but if anything shortened. From this we can conclude 
 that while the attention — owing to the lack of a preparatory 
 signal — wandered in these experiments, still the subjects were 
 capable of maintaining the state of preparation for their maxi- 
 
REACTION TIME AND MOVEMENT. 
 
 39 
 
 mum motor discharge in spite of the fluctuations of the attention. 
 The experiments in this section show that with subject B the 
 disturbance of the attention was certainly greater than was com- 
 patible with maintaining the state of preparation for the maxi- 
 mum motor discharge. With subject A this was generally but 
 not always the case. The point to be noted at present — but 
 which will be brought out more fully later — is that the state of 
 preparation for the maximum motor discharge can be main- 
 tained in the midst of fluctuations of the attention more or less 
 extensive. 
 
 *t<o* 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 / 
 
 L 
 
 
 
 
 
 / 
 
 
 
 
 
 s 
 
 
 i 
 
 / 
 
 \ 
 
 J 
 
 L 
 
 
 
 
 
 
 
 
 
 \ 
 
 / 
 
 
 \ 
 
 / 
 
 \ 
 
 / 
 
 
 
 
 
 
 
 
 \ 
 
 / 
 
 
 
 f 
 
 \ 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 \ 
 
 s 
 
 
 v % 
 
 
 ^-" 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 < r » 9 
 
 Fig. io. 
 
 Besides the interpretation of the mean values of the experi- 
 ments, it may be of interest to inquire into the variations of the 
 individual experiments. It has been pointed out by Wundt 1 
 that when a very loud signal is given for reaction it sometimes 
 seems to be of unexpected intensity, so that the subject is 
 startled and the reaction time lengthened. Though under nor- 
 
 1 'Grundziige der physiologischen Psychologies 5th ed., III., p. 430. 
 
4° THOMAS V. MOORE. 
 
 mal conditions we found no variation in the movement time con- 
 comitant with that in the reaction time, some such variation 
 might be expected in series made under disturbing influences. 
 Perhaps the shock of surprise might lengthen or shorten the 
 movement time. At any rate, if the same set of conditions 
 govern both the reaction time and the movement time we should 
 expect to find that one would vary directly or inversely as the 
 other. To bring out the relation between the individual experi- 
 ments of the series, curves have been plotted out to represent 
 the variations within each series. The continuous lines are the 
 curves of reaction time; the dotted ones, of movement time. 
 Numerals along the axis of abscisscas refer to the number of 
 each experiment in its series : those along the axis of ordinates 
 refer to time in five-hundredths of a second. 
 
 In examining the plotted curves it will appear that the longer 
 reaction times are not always followed by shorter movement 
 times. An increase in the reaction may be followed by either 
 a decrease or an increase in the movement time. And reac- 
 tions above the mean have movements above or below the mean 
 of the movement time. The supposition, therefore, that the 
 longer reaction times are due to a set of causes which also 
 govern the movement time, finds no confirmation in the plotted 
 curves. 
 
 8. Compound Reaction and the Speed of Sub- 
 sequent Movement. 
 After studying some of the disturbances of simple reaction 
 and their effect on the speed of the subsequent movement, it 
 seems to be in place to investigate the relation between com- 
 pound reaction and its movement time. Our previous experi- 
 ments have indicated that increase of mental activity augmented 
 the motor discharge of reaction. If, now, we make it necessary 
 for the subject to perform one or more psychic acts between the 
 signal for reaction and the execution of the movement, what 
 relation will exist between the time of reaction and of move- 
 ment? Will the movement time maintain its normal constancy ? 
 Will the interpolated process reinforce or tend to inhibit the sub- 
 sequent movement? 
 
REACTION TIME AND MOVEMENT. 4 1 
 
 The compound reaction selected for this test was that of 
 choice between a movement and no movement. This kind of 
 reaction is indeed simpler than that of choice between two move- 
 ments. But the more complex form has not always been found 
 to be the longer one. 1 In this form of reaction it is necessary 
 for the subject to perceive the difference between two signals, 
 and choose to react or not. If he chooses to react, these proc- 
 esses of distinction and choice must intervene between the time 
 of hearing the signal and the muscular response. 
 
 In order to make this series of experiments, a second signal 
 was arranged which gave a tap differing in sound from the 
 previous stimulus for reaction. The new sound was made by 
 letting the armature of an electromagnet fall about five milli- 
 meters on a piece of sheet-iron, forty-five centimeters square, 
 supported on four brass legs about fifteen millimeters high. 
 This piece of sheet-iron was used in other experiments for giving 
 a very loud signal. The tap made by the fall of the armature 
 was not, however, loud, but perfectly distinct. The electro- 
 magnet was worked by an independent circuit. To break this 
 current a contact-breaker could be substituted at will for the 
 metal bar on the time-sense apparatus above described. The 
 signal not to react was produced by the new arrangement. The 
 signal to react was given as in the previous experiments. 
 
 
 
 Subject A. 
 
 
 
 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M.V. 
 
 No. 
 
 I. 
 
 
 296 
 
 58 
 
 8 
 
 98 
 
 3 
 
 9 
 
 
 (Normal), 
 
 156 
 
 II 
 
 11 
 
 106 
 
 4 
 
 12 
 
 II. 
 
 
 278 
 
 29 
 
 9 
 
 104 
 
 3 
 
 13 
 
 
 (Normal), 
 
 166 
 
 26 
 
 9 
 
 "5 
 
 5 
 
 9 
 
 III. 
 
 
 215 
 
 43 
 
 8 
 
 "3 
 
 7 
 
 9 
 
 
 (Normal), 
 
 159 
 
 14 
 
 11 
 
 112 
 
 14 
 
 10 
 
 
 
 212 
 
 55 
 
 12 
 
 118 
 
 6 
 
 12 
 
 
 
 Subject B. 
 
 
 
 
 
 I. 
 
 
 294 
 
 60 
 
 9 
 
 104 
 
 8 
 
 12 
 
 
 (Normal), 
 
 i55 
 
 11 
 
 12 
 
 90 
 
 4 
 
 13 
 
 II. 
 
 
 297 
 
 5i 
 
 9 
 
 95 
 
 11 
 
 7 
 
 
 (Normal), 
 
 165 
 
 11 
 
 11 
 
 86 
 
 3 
 
 11 
 
 III. 
 
 
 381 
 
 7i 
 
 10 
 
 85 
 
 4 
 
 11 
 
 
 (Normal), 
 
 i55 
 
 15 
 
 '3 
 
 77 
 
 3 
 
 13 
 
 IV. 
 
 
 319 
 
 66 
 
 10 
 
 96 
 
 6 
 
 10 
 
 
 
 328 
 
 76 
 
 10 
 
 99 
 
 6 
 
 10 
 
 
 (Normal), 
 
 171 
 
 28 
 
 12 
 
 87 
 
 3 
 
 13 
 
 >Cf, 
 
 Wundt, ' Grundziige der 
 
 physiologischen 
 
 Psychologie 
 
 ,' 5th ed 
 
 L, III. 
 
 p. 461. 
 
 
 
 
 
 
 
 
4* THOMAS V. MOORE. 
 
 In examining these tables it will be found that for Subject 
 B the mean value of the movement time was always several 
 thousandths of a second longer when it comes as the result of a 
 compound reaction. The corresponding mean variation is also 
 lengthened. For Subject A this result occurs only in the last 
 group of series reported, and then the lengthening is but slight. 
 
 I. Series in which Subject B was Directed to Give the Greater 
 Share of His Attention Towards Reacting 
 with a Quick Movement. 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M V. 
 
 No. 
 
 I. 
 
 (Normal), 
 
 109 
 
 8 
 
 12 
 
 103 
 
 3 
 
 12 
 
 II. 
 
 
 220 
 
 24 
 
 22 
 
 98 
 
 2 
 
 24 
 
 I. 
 
 
 199 
 
 40 
 
 26 
 
 93 
 
 2 
 
 26 
 
 II. 
 
 (Normal), 
 
 130 
 
 14 
 
 IO 
 
 95 
 
 3 
 
 II 
 
 I. 
 
 (Normal), 
 
 143 
 
 16 
 
 II 
 
 94 
 
 4 
 
 II 
 
 II. 
 
 
 195 
 
 60 
 
 19 
 
 95 
 
 3 
 
 20 
 
 I. 
 
 (Normal), 
 
 I05 
 
 9 
 
 IO 
 
 102 
 
 1 
 
 9 
 
 II. 
 
 
 185 
 
 49 
 
 25 
 
 101 
 
 3 
 
 26 
 
 (From four to seven erroneous reactions occurred in each series of com- 
 pound reactions.) 
 
 II. Series in which Subject B was Instructed to Take Care to 
 
 React Only to the Right Signal ; but at the Same Time 
 
 to Make the Quickest Possible Movement. 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 I. 
 
 (Normal), 
 
 114 
 
 IO 
 
 12 
 
 96 
 
 3 
 
 12 
 
 II. 
 
 
 227 
 
 40 
 
 29 
 
 96 
 
 2 
 
 29 
 
 I. 
 
 
 269 
 
 48 
 
 25 
 
 92 
 
 I 
 
 25 
 
 II. 
 
 (Normal), 
 
 123 
 
 7 
 
 II 
 
 9S 
 
 4 
 
 II 
 
 I. 
 
 (Normal), 
 
 141 
 
 16 
 
 II 
 
 93 
 
 3 
 
 II 
 
 II. 
 
 
 256 
 
 26 
 
 IO 
 
 92 
 
 2 
 
 IO 
 
 I. 
 
 
 219 
 
 36 
 
 28 
 
 93 
 
 2 
 
 28 
 
 II. 
 
 (Normal), 
 
 158 
 
 16 
 
 12 
 
 95 
 
 13 
 
 5 
 
 (In the first part of three of these series of compound reactions the subject 
 made one erroneous reaction, but was immediately warned. After the warning 
 each series was completed without another error. ) 
 
 The compound reaction time for Subject B was longer than that 
 for Subject A. This suggested the supposition that perhaps 
 Subject B paid such attention to waiting for the signals that he 
 did not exert his maximum effort to make the quickest possible 
 movement. Accordingly, it was decided (1) to take several 
 series for this subject in which he was directed to pay more 
 attention towards reacting with a quick movement than taking 
 care to react only to the proper signal, and then (2) to direct him to 
 
REACTION TIME AND MOVEMENT. 43 
 
 take care not to make any mistakes, but at the same time to react 
 with the quickest possible movement. The results are given above. 
 
 We have here results obtained from two methods of directing 
 the attention in a compound reaction. If the attention is di- 
 rected towards making a rapid movement the reaction time is 
 quicker than when the subject directs his attention to the signal, 
 i. e., takes care to make no mistakes. The compound reac- 
 tions made under these conditions appear to have some analogy 
 to the muscular and sensorial simple reactions. But when the 
 subject is told to give the greater share of his attention towards 
 making a quick movement there is scarcely a full compound 
 reaction. The process of choice is perhaps eliminated and we 
 have in the greater part of the series a full sensorial reaction. 
 But when the subject is told to take care tha the make no mis- 
 takes we have a true compound reaction with a complete proc- 
 ess of choice interpolated. 
 
 As to the movement time there is but little difference in the 
 two sets of experiments. In both the time of movement is 
 usually a little quicker for compound reactions than for those 
 made under normal conditions. It seems that the slight in- 
 crease of mental activity demanded for the compound reaction 
 acted as a stimulus which slightly reinforced the motor dis- 
 charge. This result agrees with those obtained with Subject^, 
 but is a reversal of the results first obtained from Subject B. 
 The compound reaction times in Subject B's last two sets of 
 experiments are shorter than in his former. The most probable 
 explanation of these facts is that in his first set of experiments 
 Subject B's attention was so exclusively turned towards the 
 signal for reaction that he did not take the proper care to make 
 the movement as quick as possible. If this be true, then we 
 have in the first set of experiments from Subject B something 
 like a sensorial compound reaction and in the second set a mus- 
 cular compound reaction. 
 
 9. Relation Between the Movement of Reaction and 
 an Independent Voluntary Movement. 
 
 All the movements measured in the preceding series of 
 experiments were the immediate result of responding to the 
 
44 
 
 THOMAS V. MOORE. 
 
 stimulus for reaction. The chain of connection between the ear 
 and the muscles concerned in the movement was in some man- 
 ner prepared by a voluntary act which preceded the stimulus 
 for reacting. In those reactions that were muscular it will gen- 
 erally be admitted that no new act of the will intervened be- 
 tween the stimulus for reaction and the movement. In the sen- 
 sorial reactions (e. g-., those made without any preparatory 
 signal) there was at least some preparation for the movement, 
 by a previous act of the will, before the stimulus was given. 
 Perhaps there might be some difference in the time of move- 
 ment when it arises as the immediate result of a voluntary act 
 and not in response to a stimulus. To test this point the sub- 
 ject was told that, on hearing the signal, he should wait a short 
 time and then, after resolving to make the quickest movement 
 he could, execute it to the best of his ability. In this way a 
 movement was secured which came as the immediate result of 
 a voluntary act. Consecutive series were taken of the volun- 
 tary movement and of the reaction and its movement. As 
 usual we have grouped the consecutive series together in re- 
 porting the results below. 
 
 
 
 
 Subject A. 
 
 
 
 
 
 
 
 Reaction. M. V. 
 
 No. 
 
 Movement. 
 
 M. V. 
 
 No. 
 
 I. 
 
 
 
 
 
 115 
 
 8 
 
 24 
 
 
 (Normal), 
 
 137 
 
 23 
 
 II 
 
 113 
 
 5 
 
 14 
 
 
 (Normal), 
 
 145 
 
 14 
 
 IO 
 
 113 
 106 
 
 4 
 6 
 
 IO 
 22 
 
 
 (Normal), 
 
 123 
 
 14 
 
 IO 
 
 117 
 117 
 Il8 
 
 5 
 
 5 
 
 10 
 
 14 
 14 
 13 
 
 II. 
 
 
 
 
 
 114 
 
 8 
 
 39 
 
 
 (Normal), 
 
 159 
 
 18 
 
 IO 
 
 112 
 Il6 
 
 4 
 4 
 
 ii 
 25 
 
 III. 
 
 
 
 
 
 I07 
 
 5 
 
 24 
 
 
 (Normal), 
 
 163 
 
 26 
 Subject B. 
 
 II 
 
 I02 
 
 5 
 
 13 
 
 '.. Prep. Signal 4*4 s. 
 
 
 
 
 
 
 
 
 (Normal), 
 
 117 
 
 9 
 
 s 
 
 IOO 
 IIO 
 
 6 
 8 
 
 S 
 
 I. Prep. Signal 4 1 . s. 
 
 
 
 
 
 
 
 
 (Normal), 
 
 133 
 
 12 
 
 IO 
 
 96 
 
 ss 
 
 3 
 
 10 
 16 
 
REACTION TIME AND MOVEMENT. 45 
 
 III. Prep. Signal $% s. 
 
 (Normal), 161 46 12 
 
 IV. Prep. Signal 4^ s. 
 
 V. Prep. Signal 2 s. 
 
 136 12 10 
 
 113 26 
 
 89 
 
 1 
 
 6 
 
 91 
 
 3 
 
 12 
 
 93 
 
 0.5 
 
 4 
 
 90 
 
 3 
 
 10 
 
 95 
 
 3 
 
 10 
 
 93 
 
 3 
 
 10 
 
 92 
 
 5 
 
 27 
 
 95 
 
 4 
 
 13 
 
 95 
 
 4 
 
 16 
 
 When we examine these results it seems perfectly clear that 
 with Subject B the speed of what may be called the purely 
 voluntary movement cannot be said to be constantly quicker or 
 slower than that made in response to the signal to react. The 
 variations lean now a little to one side and now to another. The 
 mean deviation from the normal (without regard to plus or 
 minus signs, of course) is four thousandths of a second. With 
 Subject A, however, it must be noted that the normal was 
 quicker by several thousandths of a second, except in one case, 
 when the voluntary movement was seven thousandths of a second 
 quicker than the preceding normal, and four thousandths of a 
 second quicker than the succeeding normal. The mean deviation 
 from the normal for this subject is five thousandths of a second. 
 It may be noted that with Subject B the tendency towards a 
 muscular reaction is stronger than with Subject A. 
 
 The conclusion that we are justified in drawing from these 
 results is that no decided difference exists between the time of 
 a movement made in reaction and that made by a purely 
 voluntary act. 
 
 10. The Effect of Sensory Stimuli on the Time of Re- 
 action and of Movement. 
 
 Before presenting the results obtained in this part of the 
 work, it will be well to give some account of the literature which 
 bears upon the effect of various stimuli on voluntary movement. 
 
 One of the earliest and most extensive workers in this line is 
 M. Charles Fere. The first edition of his * Sensation et Mouve- 
 ment' was published in 1887. In that work he put forward a 
 number of conclusions at which he had arrived by means of his 
 
46 THOMAS V. MOORE. 
 
 experiments with the dynamometer. He there published the 
 opinion that * momentary exercise of the mind provokes a mo- 
 mentary exaggeration of voluntary movements.' l He also found 
 that the exercise of any group of muscles other than those used 
 in working the dynamometer increased the force of the hand a 
 sixth or a fifth part or even more. Speaking produced a like 
 effect. He also studied the influence of the suggestion of a 
 movement on subjects abnormally affected by excitatory or de- 
 pressive agents. Such a subject could be made to feel a move- 
 ment in his own hand and finally to execute irresistible, rhythmic 
 flexions, merely by watching the movements of the experimenter. 
 If, however, at the point where the subject commenced to feel 
 the sensation of movement, his hand were placed in the dyna- 
 mometer, the force of movement then registered would be a 
 third or a half greater than the normal pressure. M. Fere con- 
 cluded from these and certain other experiments that ' the energy 
 of a movement is in relation with the intensity of its mental 
 representation.' 2 He also found that the shorter the wave-length 
 and the greater the amplitude of wave-length in a sound, the 
 greater was its power to reinforce movement. 3 Similar results 
 were found to hold good for light stimuli. 4 
 
 M. Fere" continued this line of work by subsequent researches 
 with Mosso's ergograph. One of these pieces of work, which 
 deals with the effect of a number of sensory stimuli, was pub- 
 lished in 1901 , in the Journal de V Anatomic et dc la Pkysiolog 
 The method of procedure in the experiments there reported was : 
 
 1. The reaction times of two index lingers and of the left 
 middle finger were taken. 
 
 2. Two records of pressure were taken from each hand 
 on the dynamometer. 
 
 3. The middle finger of the left hand was placed in the 
 dynamometer and a weight of three kilograms was lifted 
 every second. It is not stated that each series was limited 
 by the exhaustion of the middle finger. 
 
 a P. 7- 
 
 2 Op. at., p. 14. 
 
 3 Op.cit., p. 34, ff. 
 
 *Op. cit., p. 41, ff. 
 
 6 Vol. XXXVII., pp. 1-79. 
 
REACTION TIME AND MOVEMENT. 47 
 
 4. A rest of three minutes was allowed, during which 
 each hand was again tested on the dynamometer. A new 
 series was then begun and this method of procedure con- 
 tinued through a number of series, varying from seven to 
 sixty. 
 
 5. At the end of the whole set the pressure of each hand 
 was again taken, and the reaction time of the two index and 
 the left middle fingers were again taken. 
 
 The results indicated an oscillation in fatigue throughout the 
 various sets of experiments. The pressure of the left hand 
 steadily diminished ; but at the end of four or five series that of 
 the right hand was often augmented. At the end of the ex- 
 periment the reaction time of the two index fingers was found to 
 be less than at the beginning ; but that of the middle finger was 
 increased. It was also found that moving the legs and counting 
 in a loud voice reinforced the working-finger. More work 
 could be done with the eyes open than closed, and more under 
 the influence of red light than any other. Sounds both har- 
 monious and discordant increased the power of working. Musk 
 and ethereal odors, the taste of sugar, acetic acid and sulphate 
 of quinine all reinforced the working finger. Alcohol and 
 bouillon merely taken into the mouth increased the amount of 
 work that could be done more than when swallowed. Tastes 
 were found, as a rule, to reinforce the working finger more than 
 odors, and both together operated more powerfully than either 
 separately. Cutaneous sensations, such as heat, cold, and rub- 
 bing, had also a tonic effect. 
 
 In another article in the same volume of this magazine, M. 
 Fere came to these conclusions : " Le travail mecanique de la 
 main gauche est moins influence par le travail intellectuel que le 
 travail mecanique de la main droite. Le travail de la main 
 gauche gagne moins quand il coincide avec un travail intel- 
 lectuel facile, il perde moins quand il coincide avec un travail 
 intellectuel relativement complique." 
 
 M. Fere has made a number of other studies in the rein- 
 forcement of voluntary muscular contractions ; but it will not be 
 necessary to summarize them here. A number of them will 
 find mention in the bibliography. Those already reported show 
 the general trend of his line of work. 
 
48 THOMAS V. MOORE. 
 
 Ludwig Hofbauer 1 found that loud raps, the slamming of a 
 door or such sound stimuli, were too weak to make any mani- 
 fest change in an ergogram. Consequently he tried the sound 
 made by firing a revolver. The contraction recorded after 
 such a loud report usually jutted far above those before or after 
 it. On closer examination it was found that when the report 
 came less than .4 of a second before the ordinary signal for 
 contraction, the contraction was nearly always reinforced. 
 But if a longer time intervened the contraction was somewhat 
 lessened. When the report came from .27 to .49 of a second 
 after the ordinary signal the contraction was reinforced. From 
 these and other experiments made with visual and cutaneous 
 stimuli he came to the conclusion that if the excessive stimulus 
 comes when the attention is focused upon a movement about to 
 be performed it reinforces the movement. But if the excessive 
 stimulus comes before the will is prepared to act then the volun- 
 tary movement is inhibited. 
 
 Mr. Allen Cleghorn repeated the same work, confirming 
 the results of Hofbauer, and also called attention to the fact 
 that the relaxation following such a reinforced contraction is 
 quicker and more complete than when no stimulus is given. ■ 
 
 Most of the literature on the reinforcement of voluntary 
 muscular contractions is, as a rule, professedly concerned with 
 fatigue rather than problems of reinforcement and inhibition. 
 And, indeed, in all work with the ergograph, such as that of 
 M. Fe're', it may be questioned whether or not the sensorial 
 stimulus directly reinforces the movement, or whether it does so 
 indirectly by tending to eliminate one of the several factors 
 which help to bring about fatigue. The effect of alcohol on 
 reaction time and ergographic work has been the subject of 
 much experimental research. Its working is, no doubt, of a 
 much more complicated character than that of a mere sensory 
 stimulus. 
 
 It is certainly desirable to study the reinforcement of volun- 
 tary muscular contractions under simpler conditions than those 
 
 1 'Interferenz zwischen verschiedenen Inipulsen iru Centralnervensvstem,' 
 Pfliiger*s Archiv fiir die ges. F . Vol. LXVIIL. pp. 546- 
 
 1 American Journal of Physiology, 1S9S. Vol. I., pp. ; 
 
REACTION TIME AND MOVEMENT. 49 
 
 offered by the ergograph. We cannot be sure that stimuli 
 which strengthen muscular contractions under the influence of 
 an ever-increasing fatigue will have the same effect on single 
 voluntary contractions when the element of fatigue is practically 
 eliminated. The apparatus already used in these experiments 
 affords the opportunity of studying the effects of sensory stimuli 
 on single voluntary contractions. Not only can we study the 
 single contractions, but also the reaction of which they are the 
 result. And an interesting problem at once presents itself : will 
 sensory stimuli which quicken or lengthen reaction time have 
 the same effect on the time of the subsequent movement? 
 
 The stimuli which have been studied are : 
 
 (a) A continuous noise made by the interrupter of an induc- 
 tion coil. 
 
 (p) The noise of this induction coil plus a slight shock 
 received by holding the electrodes in the hand. This 
 shock was not painful. 
 
 (c) An intermittent sound made by a metronome beating 
 sounds. 
 
 (d) A very loud signal for reaction. 
 
 To give this loud signal, some additions to the apparatus 
 already employed were required. A hammer was pivoted so 
 that it could fall through an angle of sixty degrees on the plate 
 of sheet-iron mentioned above. 1 In one corner of this plate a 
 spring made of phosphor-bronze was fastened to an insulated 
 support. The other end could be held up from the plate of 
 sheet-iron on an insulated latch. When the hammer fell, it 
 drove the spring down upon the plate of sheet-iron, giving at 
 the same time, as a signal for reaction, a single loud report. 
 An electric contact was thereby established through wires run- 
 ning from the metal plate and the spring. This contrivance was 
 substituted for the electromagnetic sound-hammer in the circuit 
 above described. 2 The hammer which fell on the metal plate 
 could be held in an almost upright position by means of an 
 electromagnet. Breaking this circuit let the hammer fall until 
 it hit the spring. The plate of sheet-iron rested on a wooden 
 
 *P. 41. 
 2 P. 14 ff. 
 
50 THOMAS V. MOORE. 
 
 box, which served as a sounding-board. Its level being some- 
 what above that of the hammer's pivot, the extent of the swing 
 was limited to about sixty degrees. 
 
 It was found necessary to introduce this spring for making 
 an electric contact with the plate, rather than to have it estab- 
 lished directly through the hammer. The first experiments 
 were made by the latter method ; but the rebound of the ham- 
 mer falling through so great a distance falsified the results of 
 the reaction time. These early series, however, are published 
 below, the reaction time for the loud signal being omitted. The 
 time of movement, however, could not be effected by the re- 
 bound of the hammer, for the contact must be made by the time 
 the subject commences to react, or no record at all is obtained. 
 
 The results are divided into sections. The effect of the 
 sound of the induction coil and the shock were studied together 
 and form a single section. 
 
 Section A. The effect of a continuous sound and of a contin- 
 uous electric shock o?i reaction time and movement time. 
 
 Subject A. 
 Series I. Disturbance Caused by the Sound of an Induction Coil. 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M V. 
 
 No. 
 
 202 
 
 36 
 
 9 125 
 Series II. Normal. 
 
 4 
 
 IO 
 
 Reaction. 
 
 IE. V. 
 
 No. Movement. 
 
 M. V. 
 
 No. 
 
 164 
 
 18 
 
 13 I20 
 
 5 
 
 14 
 
 ts III. Disturbance Caused by the Sound of an Induction Coil and a < 
 
 
 
 tinuous Shock. 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M. V. 
 
 No. 
 
 177 
 
 23 
 
 12 127 
 
 s IV. Same as Series I. 
 
 II 
 
 13 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M. V. 
 
 No. 
 
 162 
 
 II 
 
 13 II6 
 
 Series V. Normal. 
 
 6 
 
 Io 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M V. 
 
 
 146 
 
 17 
 
 14 112 
 
 5 
 
 14 
 
 
 Series VI. Same as Series III 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M. V 
 
 
 166 
 
 IS 
 
 IO 119 
 
 4 
 
 II 
 
REACTION TIME AND MOVEMENT. 
 
 5* 
 
 
 
 Subject A. 
 
 
 
 
 
 Series I. Normal. 
 
 
 
 Reaction. 
 
 M. V. 
 
 No. Movement. 
 
 M. V. 
 
 No. 
 
 I68 1 
 
 20 
 
 12 IIO 
 
 6 
 
 '3 
 
 Series II. Disturbance Caused by the Sound of an Induction Coil. 
 
 Reaction. M. V. No. Movement. M. V. No. 
 
 169 9 9 114 6 12 
 
 Series III. Disturbance Caused by the Sound of an Induction Coil and a 
 Continuous Shock. 
 
 Reaction. 
 173 
 
 M. V. No. Movement. 
 18 13 I20 
 
 M V. 
 6 
 
 No. 
 13 
 
 Reaction. 
 160 
 
 Series IV. Normal. 
 
 M. V. No. Movement. 
 14 12 III 
 
 M. V. 
 
 4 
 
 No. 
 12 
 
 Reaction. 
 166 
 
 Series V. Same as Series II. 
 
 M. V. No. Movement. 
 17 12 114 
 
 M. V. 
 
 7 
 
 No. 
 13 
 
 Reaction. 
 172 
 
 Series VI. Same as Series III. 
 
 M. V. No. Movement. 
 13 12 125 
 
 M. V. 
 
 3 
 
 No. 
 13 
 
 Reaction. 
 145 
 
 M. V. 
 16 
 
 M. V. 
 
 6 
 
 No. 
 13 
 
 Subject B. 
 Series I. Normal. 
 
 No. Movement. 
 
 13 84 
 
 Series II. Disturbance Caused by the Sound of an Induction Coil. 
 
 Reaction. M. V. No. Movement. M. V. No. 
 
 179 17 12 84 3 13 
 
 Subject C. 
 Series I. Disturbance Caused by the Sound of an Induction Coil. 
 
 Series II. 
 
 No. 
 
 13 
 Series I. Disturbance Caused by the Sound of an Induction. 
 
 Reaction. 
 164 
 
 M. V. 
 17 
 
 Reaction. 
 151 
 
 M. V. 
 18 
 
 Series I. 
 
 Reaction. 
 169 
 
 Dish 
 
 M. V. 
 
 II 
 
 Reaction. 
 156 
 
 M. V. 
 
 17 
 
 Series III. 
 
 Disti 
 
 Reaction. 
 172 
 
 M. V. 
 
 8 
 
 No. 
 12 
 
 Movement. 
 87 
 
 Normal. 
 Movement. 
 83 
 
 M. V. 
 
 4 
 
 M. V. 
 
 4 
 
 No. 
 12 
 
 Movement. 
 98 
 
 M. V. 
 
 7 
 
 No. 
 13 
 
 No. 
 13 
 
 No. 
 12 
 
 Series II. Normal. 
 
 No. Movement. M. V. No. 
 
 13 117 7 12 
 
 Disturbance Caused by the Sound of an Induction Coil 
 and a Continuous Shock. 
 
 No. Movement. M. V. No. 
 
 12 113 8 13 
 
 1 A very long reaction (266) if excluded here would bring this mean down 
 to 159. 
 
52 
 
 THOMAS V. MOORE. 
 
 Subject D. 
 
 Series I. Disturbance Caused by the Sound of an Induction Coil and a 
 
 Continuous Shock. 
 
 Reaction. M. V. No. Movement M. V. No. 
 
 212 45 io 105 8 9 
 
 Series II. Disturbance Caused by the Sound of an Induction Coil. 
 
 Reaction. 
 
 M. V. 
 
 162 
 
 12 
 
 Reaction. 
 
 M. V. 
 
 I 9 I 
 
 26 
 
 Reaction. 
 
 M. V 
 
 232 
 
 34 
 
 Reaction. 
 
 If. V. 
 
 170 
 
 16 
 
 Movement. 
 IOO 
 
 Normal. 
 Movement. 
 97 
 
 M. V. 
 
 6 
 
 M. V. 
 
 3 
 
 M. V. 
 
 7 
 
 No. 
 12 
 
 No. 
 13 
 
 No 
 14 
 
 No 
 13 
 
 No. Movement. M. V. 
 
 12 IOO 2 
 
 Series III. 
 
 No. 
 
 12 
 Series IV. Same as Series I. 
 
 No. Movement. 
 
 14 103 
 
 Subject D. 
 Series I. Normal. 
 No. Movement. 
 
 13 93 
 Series II. Disturbance Caused by the Sound of an Induction Coil. 
 
 Reaction. M. V. No. Movement. M. V. No 
 
 165 13 13 95 3 13 
 
 Series III. Disturbance Caused by the Sound of an Induction Coil, and Con- 
 tinuous Shock. 
 
 M. V. Movement. M V. No. 
 
 16 12 95 4 12 
 
 The Effect of an Intermittent Sound on Reaction 
 Time and Movement Time. 
 The intermittent sound, as we have said, was caused by a 
 metronome beating sounds. 
 
 Reaction. 
 173 
 
 Section B. 
 
 
 
 Subject 
 
 B. 
 
 
 
 
 
 Reaction. 
 
 M. V 
 
 No. 
 
 Movement 
 
 M V 
 
 
 (Normal), 
 
 153 
 
 39 
 
 S 
 
 89 
 
 3 
 
 8 
 
 
 166 
 
 28 
 
 II 
 
 91 
 
 3 
 
 11 
 
 (Normal), 
 
 164 
 
 30 
 Subject 
 
 9 
 D. 
 
 93 
 
 3 
 
 8 
 
 (Normal), 
 
 14S 
 
 16 
 
 12 
 
 104 
 
 5 
 
 12 
 
 
 240 
 
 30 
 
 9 
 
 112 
 
 4 
 
 11 
 
 
 190 
 
 20 
 
 12 
 
 in 
 
 4 
 
 13 
 
 (Normal), 
 
 164 
 
 27 
 
 12 
 
 113 
 
 4 
 
 12 
 
 
 179 
 
 20 
 
 11 
 
 105 
 
 3 
 
 
 Section C. 
 
 The Effect of a Loud Signal for Reaction. 
 
 
 
 S UBJECT 
 
 A. 
 
 
 
 
 
 Reaction. 
 
 M V. 
 
 No. 
 
 Movement. 
 
 
 
 I. 
 
 154 
 
 19 
 
 26 
 
 99 
 
 5 
 
 
 (Normal), 
 
 129 
 
 16 
 
 9 
 
 104 
 
 2 
 
 10 
 
REACTION TIME AND MOVEMENT. 53 
 
 II. 
 
 153 
 
 19 
 
 34 
 
 106 
 
 3 
 
 25 
 
 (Normal), 
 
 180 
 
 27 
 
 10 
 
 121 
 
 5 
 
 11 
 
 
 166 
 
 32 
 
 26 
 
 101 
 
 6 
 
 27 
 
 
 158 
 
 17 
 Subject 
 
 38 
 B. 
 
 98 
 80 
 
 4 
 4 
 
 37 
 12 
 
 (Normal), 
 
 147 
 
 14 
 
 11 
 
 98 
 100 
 
 5 
 
 4 
 
 12 
 12 
 
 (Normal), 
 
 
 
 
 93 
 
 1 
 
 18 
 
 
 
 Subject C. 
 
 
 
 
 
 
 
 
 90 
 
 4 
 
 10 
 
 (Normal), 
 
 142 
 
 14 
 
 13 
 
 102 
 
 4 
 
 13 
 
 In examining these results it seems clear that when a sensory 
 stimulus was given continuously during a series of experiments 
 the reaction time was usually lengthened. This was most evi- 
 dent when the subject heard the sound of an induction coil, and 
 also felt the shock by holding the electrodes in his left hand. 
 The lengthening of the reaction time due to the sound of the 
 coil alone was generally less than that caused by both the sound 
 and the shock together. The effect on the movement time was 
 not so marked ; but it seemed that a continuous sensory stimulus 
 tends to lengthen the time of movement. And, as a rule, the 
 lengthening of the movement time — as of reaction time — was 
 greater for the two disturbances than for one alone. 
 
 The effect of the intermittent sound was to lengthen reaction 
 time, but no effect on the movement time could be ascertained. 
 The meaning of this is that the intermittent sound acts merely 
 as a disturbance of the attention. 
 
 The effect of the loud signal for reaction was without ex- 
 ception to quicken the time of movement. Its effect on the time 
 of reaction was not constant. 
 
 11. The Graphic Curve of the Movement. 
 A complete study of the movement of reaction should give 
 us not only the absolute time of the movement and its variation 
 in a series of experiments, but also the variation in the speed 
 movement throughout its entire course. Does the movement 
 start with a maximum velocity and then gradually decrease? 
 Or is the speed constantly accelerated? Does it vary irregu- 
 larly? The best way of solving this question is of course to get 
 
54 
 
 THOMAS V. MOORE. 
 
 a graphic curve by which the 
 movement will be represented in 
 coordinates of time and space. 
 To obtain this curve the follow- 
 ing apparatus was used. A 
 piece of heavy steel wire 104 cm. 
 long and 2.1 mm. in diameter 
 was arranged to run through two 
 eye-holes, one in each of two 
 brass rods supported on stands, 
 beside the drum of a chrono- 
 graph. This drum was 35.5 cm. 
 long and 16 cm. in diameter. In 
 the middle of the rod of steel wire 
 a brass marker was soldered, 
 which reached over to the top of 
 the drum. The brass rods which 
 supported the steel wire were so 
 arranged that it ran through the 
 eye-holes without friction, in a 
 line parallel to the axis of the 
 drum. When the drum was at 
 rest and the steel rod was drawn 
 through the eye-holes, it made 
 of course a perfectly straight 
 line along the top of the drum. 
 When, however, the drum was 
 in motion, a curve was drawn 
 which varied with the speed of 
 the drum and the rate at which 
 the wire passed through the eye- 
 holes. The speed of the drum, 
 however, was nearly constant, 
 and with the gearing and weights 
 used it made sixty revolutions a 
 minute. Through a small eve- 
 hole in the end of the wire, 
 a heavy linen thread 
 
REACTION TIME AND MOVEMENT. 55 
 
 through pulleys to the lever which the subject moved in making 
 the movement. To the other end of the wire a long, loosely- 
 wound steel spring was attached and passed backward to the 
 wall. This served to keep the linen thread taut and make the 
 wire follow the movement of the arm, whether it moved fast or 
 slowly, backwards or forwards. Its pull against the arm, how- 
 ever, was too slight to have any appreciable effect on the move- 
 ment. The drum being in motion, a graphic curve was ob- 
 tained of whatever movement was made with the lever. A 
 sample curve is here reproduced (Fig. n). 
 
 In examining this curve, we find that during the first part of 
 its course it is concave to a line drawn from the starting-point 
 of the curve with the drum at rest. This shows that during 
 this part of the curve, the movement was accelerated. It 
 passes, however, into an approximately straight line before 
 reaching the end of twenty degrees. This shows that at the 
 point of transition the speed of movement attains its maximum 
 and after this remains almost constant. 
 
 A number of curves were taken with the drum moving at a 
 slower rate of speed, to see if the • antagonistic reaction ' noticed 
 with some persons by Mr. Smith 1 would be found in the move- 
 ments of our subjects. Only Subject A knew beforehand the 
 purpose of the experiments. In these experiments the starting- 
 point was a little away from the post to allow for any possible 
 antagonistic movement. Though the slightest backward move- 
 ment would have been recorded on the drum, no ' antagonistic 
 reaction ' was found for our subjects. 
 
 Summary. 
 
 The empirical conclusions thus far reached may be sum- 
 marized as follows : 
 
 i. When the subject is told to react as quickly as possible 
 but nothing is said about the movement of reaction, whether it 
 is to be fast or slow, there is no fixed relation between the reac- 
 tion time and the movement time. The variations in one seem 
 to be independent of those in the other. 
 
 1 Cf. supra, p. 3. 
 
56 THOMAS V. MOORE. 
 
 2. When, however, the subject is told to react as quickly as 
 possible with the quickest possible movement, the time of move- 
 ment is practically constant, but the reaction time may vary 
 considerably. 
 
 3. The idea of making the quickest possible movement has 
 a tendency to make the subject react in the muscular manner. 
 
 4. There is no constant relation between the slight varia- 
 tions in reaction time and the larger variations in the movement 
 time, or, in other words, the slower movements do not corre- 
 spond to the longer reactions, nor do the slower movements 
 correspond to the quicker reactions. 
 
 5. With some subjects this comparative constancy in the 
 movement time is attained with little or no practice. 
 
 6. Varying the preparatory signal in successive series from 
 one to three seconds causes the reaction time to change, but 
 does not seem to affect the movement time. 
 
 7. When no preparatory signal at all is given, and when it 
 is given at irregular intervals, the reaction time is considerably 
 lengthened. The movement time is not lengthened, however, 
 but is if anything a little shorter. 
 
 8. The disturbance of the attention caused by having the 
 subject carry on a process of addition is in general greater than 
 is compatible with executing the quickest possible movement. 
 
 9. In compound reactions, when the subject had to choose 
 between a movement and no movement, the movement was 
 generally quicker than in the normal simple reaction. 
 
 10. An exception was pointed out to the above conclusion 
 which indicated also that the length of a compound reaction 
 varies according to the direction of the attention. 
 
 11. There seems to be no considerable difference in time 
 between a purely voluntary movement and that made in response 
 to a stimulus for reaction. 
 
 12. The effect of a continuous noise made during a series 
 of experiments by the interrupter of an induction coil was to 
 lengthen the reaction time, and also to a slight extent the move- 
 ment time. 
 
 13. The effect of this same noise plus a slight shock, re- 
 ceived by holding the electrodes in the left hand, was to lengthen 
 
REACTION TIME AND MOVEMENT. S7 
 
 still more the reaction time. In like manner, the movement 
 made under the influence of two disturbances was as a rule 
 slower than that executed during a single disturbance. 
 
 14. The effect of an intermittent sound, made by a metro- 
 nome beating seconds, was to lengthen the reaction time, but 
 there was no apparent effect on the movement time. 
 
 15. A very loud signal for reaction was followed by a 
 quicker movement than that of reactions made with the usual 
 tap of the hammer. 
 
VI. THEORETICAL INTERPRETATIONS. 
 
 The conclusions we have just laid down are the condensed 
 expression of the facts obtained in a number of experiments. 
 It remains now to see what bearing they may have on questions 
 of a more general character. 
 
 i. The Physiological Interpretation of Constancy 
 
 of the Movement Time. 
 
 The first point which strikes our attention in these results is 
 the variability of reaction time and the constancy of the move- 
 ment time. In one and the same series the reaction time under- 
 goes considerable change, but the movement time is fairly 
 constant. If you introduce factors which increase the difficulty 
 of attention, the reaction time is lengthened and rendered still 
 more variable, but the time of movement remains about the 
 same. Disturbances of the attention (within certain limits), 
 therefore, lengthen reaction time but do not affect the speed of 
 subsequent movement. If, now, we can find by what processes 
 of reaction the movement is determined, we can argue that they 
 are not affected by the fluctuation of the attention. 
 
 It is clear that the velocity of the movement is determined 
 by the intensity of the motor discharge received in the muscles. 
 Following this discharge back, we find that it is determined by 
 the discharge of the root-cells in the grey matter of the spinal 
 cord. Tracing the nervous impulse still further, it seems prob- 
 able l that it received a certain amount of coordination in the 
 bulb, to which it came from some higher center. And as we 
 shall see later, this higher center is most likely the cortex. 
 Constancy in the speed of movement would therefore be de- 
 pendent upon constancy in the discharge of root-cells, invari- 
 ably the same distribution in the bulb, and constancy in the 
 discharge of the cortical cells. If we found that the speed of 
 movement was lengthened by a disturbance of the attention, we 
 
 1 Cf. Foster, ' A Text Book of Physiology,' 5th ed., New York. 1S90, Part 
 III., Section VI. 
 
 (58) 
 
REACTION TIME AND MOVEMENT. 59 
 
 might infer — at least as far as logic is concerned — that either 
 the cortical cells or the bulb or the root-cells of the spinal column 
 were affected by the disturbance of the attention. For a slower 
 movement would be due either to a weaker discharge of cortical 
 cells or spinal root-cells, or to an improper distribution in the 
 bulb, by which some of the discharge would be dissipated along 
 the wrong paths. Since, however, in spite of the disturbances 
 of the attention, the speed of movement remains constant, we 
 must suppose that cortex, bulb and root-cells continue to function 
 just as they do under normal conditions. 
 
 Now, this might be explained in two ways. In the first 
 place, we might suppose that the disturbance of the attention 
 actually does result in a relaxation of the maximum motor dis- 
 charge. But before making the movement, the attention of the 
 subject was again focused upon the idea of making the quick- 
 est possible movement and then by a new act of the will his 
 maximum motor discharge was again prepared and sent forth to 
 the muscles. 
 
 But against this view may be urged the conclusion from one 
 set of experiments in compound reaction. In these experi- 
 ments a choice was to be made between a movement and no 
 movement. It was found that while the subject endeavored to 
 react with the quickest possible movement, he executed a slower 
 movement than in a normal simple reaction. The idea of not 
 making a movement most likely brought about a relaxation of 
 the preparation for the maximum discharge. A new act of the 
 will was undoubtedly present in this compound reaction to exe- 
 cute the quickest possible movement; but it seems to have 
 failed to do so. And there seems to be no reason to expect 
 that after a disturbance of the attention the subject would, as it 
 were, wait to re-establish the best conditions for a rapid move- 
 ment and then execute it. Another idea also would be present 
 in consciousness : to start as soon as possible. Without wait- 
 ing for any complicated process to take place, the subject would 
 react at once and make the movement — as in the set of com- 
 pound reactions referred to — as best he could under the condi- 
 tions. The processes of a new act of the will and re-prepara- 
 tion of the motor discharge complicate the process of reacting 
 
60 THOMAS V. MOORE. 
 
 too much. Some simpler explanation is probably the truer ex- 
 pression of what really takes place. 
 
 The other hypothesis which might be offered is that the sub- 
 ject can maintain the state of motor tension for the movement 
 in the midst of such wanderings of the attention as occur when 
 no preparatory signal is given and sometimes even while the 
 attention is employed in such a process as addition. Of course 
 a complete state of inattention would excessively lengthen the 
 reaction time, during which period the maximum motor dis- 
 charge might or might not be prepared for the execution of the 
 movement. 
 
 However, the attention was by no means completely dis- 
 tracted during these series of experiments. Its wanderings 
 were comparatively slight and we may say insufficient to dis- 
 turb the motor preparation for the quickest possible movement. 
 The central disturbance resulted in a lengthening of reaction 
 time which was due to changes in the central stations or per- 
 haps in the afferent paths. That the efferent path from cortex 
 to muscle is not affected by the disturbance of the attention and 
 that reaction time is not lengthened by any changed conditions 
 along this path, seem to be the conclusions warranted by the 
 fact of constancy in the time of the movement by which the 
 reaction was executed. But can we apply the latter conclusion 
 to reactions where there is no attempt to make the quickest pos- 
 sible movement? Have we not found that in such reactions the 
 time of movement varies? But the variations in the time of 
 movement when the subject does not try to make it fast or slow, 
 are due to the varying intensity of discharge which the motor 
 center happens to send forth — not of course to any varying 
 resistance in the efferent paths. And there seems to be no 
 reason to suppose that in one case attention would affect the 
 efferent paths and in the other case it would not. Nor should 
 we expect a lengthening of reaction time in the efferent circuit. 
 The axones of the motor cells in the cortical area pass down 
 through the pyramidal tract to the root-cells in the spinal cord 
 without stopping at any relay station in their course. Once ■ 
 motor discharge is sent forth it is hard to see how any delay 
 could be experienced owing to a previous disturbance of the 
 
REACTION TIME AND MOVEMENT. 6 1 
 
 attention. With the efferent circuit, however, matters are dif- 
 ferent. The path is made up of several superimposed neu- 
 rones. And one could easily imagine that if the subject were 
 not expecting the signal for reaction the connections between 
 these neurones might be interfered with so that the stimulus 
 would be delayed in its path to the center. 
 
 2. Physiological Interpretation of the Variations of 
 
 the Movement Time Under the Influence 
 
 of Sensory Stimuli. 
 
 If it be true that a mere disturbance of the attention does 
 not interfere with the motor processes of reaction, then it must 
 be admitted that the sensory stimuli, which seemed to lengthen 
 the movement time as well as the reaction time, were probably 
 more than mere distractions of the attention. It would seem 
 that a continuous noise during a series of reactions in some 
 manner either lessened the amount of potential energy at the 
 disposal of the motor center or antagonized the maximum motor 
 discharge after it has passed outward to the muscles. Perhaps 
 the truest expression of what happened is that the sensory and 
 motor centers are so closely connected that the motor center 
 cannot do its maximum work while the sensory is continuously 
 employed. In those experiments where the sound of the induc- 
 tion coil or the shock of the electrodes or both acted as disturb- 
 ing influences, certain sensory centers were continuously at 
 work throughout each series. This is one fact. The second 
 is that the maximum discharge of the motor center was lessened. 
 The supposition just suggested seems to be the mere statement 
 of these two facts in theoretical terms. The only possible ob- 
 jection arises from the alternative already mentioned. Per- 
 haps the center of the discharge is not interfered with at all. 
 The sensory discharge flows over into a motor discharge which 
 antagonizes that of the motor center for the movement. But 
 why should that discharge be an antagonistic discharge? Why 
 should it not flow along paths already open, and reinforce the 
 movement? M. Fere found that working a set of muscles other 
 than that employed on the ergograph reinforced the working 
 finger. It is indeed hard to see why the motor discharge ac- 
 
62 THOMAS V. MOORE. 
 
 companying the continuous operation of the cutaneous" and 
 auditory centers should have an antagonistic effect upon the 
 outward rotation of the arm, unless these centers were in some 
 way closely connected with the muscles which give the humerus 
 an inward rotation — a supposition for which there is no ground 
 whatsoever. 
 
 It would seem more probable, therefore, to say that a con- 
 tinuous operation of the cutaneous and auditory centers lessens 
 the amount of potential energy at the immediate disposal of the 
 motor center for the arm. 
 
 The reinforcement of the movement by the loud signal for 
 reaction is not against this view of the matter but brings out 
 more clearly the close connection between the sensory and 
 motor areas. When the subject is waiting to respond to the 
 signal to react, we can readily suppose that the connections be- 
 tween the sensor}' and motor areas are already prepared. When 
 the incoming stimulus is very loud, the auditory center is dis- 
 charged with great force. The extra energy thus liberated 
 passes over to the motor center, discharging it more forcibly and 
 producing a quicker movement. The signal for reaction is 
 necessarily associated with the motor area for the movement. 
 We should therefore expect that the louder signal would rein- 
 force the motor area. But the sound of the induction coil or 
 the shock of the electrodes are not in any way associated with 
 the movement. The sensory discharge of those centers does 
 not therefore reinforce the motor area for the arm, but by main- 
 taining a state of neural tension in the sensory cells in some 
 manner lessens the maximum tension in the motor cells. 
 
 3. Bearing of Experiments on Professor Mcnster- 
 berg's Action-Theory. 
 
 While one may admit that (as our experiments seem to prove) 
 sensory and even intellectual representative processes ha\ 
 tendency to flow over into movement, still it would be a further 
 and bolder step to say that consciousness is absolutely depen- 
 dent on the possibility of a motor discharge. One might with 
 perfect logic admit the former and deny the latter as a con- 
 clusion too broad for the present basis oi facts. The th. 
 
 
REACTION TIME AND MOVEMENT. 63 
 
 that consciousness is absolutely dependent on the possibility of 
 a motor discharge is associated with the name of Dr. Munster- 
 berg. He has outlined his position in the last chapter of his 
 1 Grundziige der Psychologic' The above discussions of the 
 relations between the fluctuations of attention and the motor 
 discharge in reaction are suggestive of certain objections which 
 it may not be out of place to mention. But before doing so it 
 will be necessary to give some account of the peculiar theory 
 of which Professor Miinsterberg may be regarded as the author, 
 although in many of its features it is not new. 
 
 (a) Outline of the Theory. 
 
 Professor Miinsterberg has called his explanation of con- 
 sciousness the action-theory, because it makes use of motor proc- 
 esses in accounting for psychophysical phenomena. Previous 
 theories have contented themselves with centripetal processes ; 
 the action-theory makes use of the centrifugal processes as well. 
 According to the association-theory the orientation of conscious- 
 ness (Stellungnahme) is dependent on purely psychical func- 
 tions ; but Dr. Miinsterberg considers as fundamental the motor 
 functions of the brain and even real actions of the organism. 
 The new theory boasts of no recent physiological discovery as 
 its protector. It hopes to win adherents on the field of battle. 
 It starts out from the well-known facts of vividness and pene- 
 tration, of reinforcement and inhibition, of furtherance and sup- 
 pression, and associates with these the physiological processes 
 of centrifugal action. To a certain extent it accords with the 
 older theory of association. It admits that the quality of sen- 
 sation is determined by the efferent path, and the quantity by 
 the intensity of the incoming stimulation. But to explain its 
 peculiar accompanying characteristics (Wertnuance) and the 
 liveliness with which it affects consciousness, Dr. Miinsterberg 
 calls into his service the motor side of the process. 
 
 The very condition for any psychophysical phenomenon is 
 the possibility of a motor discharge. When the afferent stimu- 
 lus flows over into an efferent discharge it awakens conscious- 
 ness to action. And it is this very act of passing which makes 
 the subject conscious. If the proper motor discharge were 
 
64 THOMAS V. MOORE. 
 
 completely blocked, stimulus after stimulus might impinge upon 
 the organ of sense and be carried to the brain, and still the sub- 
 ject would know nothing of the afferent process. That we 
 may not be able to notice any motor disturbance as a result of 
 conscious processes is no conclusive argument against the 
 theory. Plethysmographic researches have pointed out the 
 connection between psychophysical work and changes in blood 
 volume ; and the study of the knee-jerk has shown how re- 
 markably the reflex centers are dependent on states of conscious- 
 ness. 
 
 Turning to physiology for a closer view of motor proc- 
 esses, it is found that the cortex does not send its impulse 
 directly to the muscle, but first acts upon certain subcortical 
 centers. These in their turn may transmit the impulse to 
 medullar ganglions. On this position of physiology the action- 
 theory finds a foothold, and lays down the further statement 
 that each subcortical motor center is connected with an antagon- 
 istic center. No central motor impulse is known which is not 
 associated with an antagonistic discharge. The typical exam- 
 ple of this is the relation between the muscles of flexion and ex- 
 tension. All antagonistic functions of the nervous system, all 
 reinforcement and inhibition, rest upon this opposition of actions. 
 " But there is no psychophysical event which as such is op- 
 posed to another psychophysical event, there are no two ideas 
 which, as psychical images, exclude each other. There are 
 no two sensations in whose very nature it lies that they cannot 
 be simultaneously present in consciousness. vl 
 
 It is on this account that any attempt to explain the pheno- 
 menon of reinforcement and inhibition from the relation between 
 sensory processes is preordained to failure. " There is but one 
 opposition, that which is based upon mechanical necessity. We 
 cannot perform one action and at the same time execute the 
 antagonistic, we cannot at the same time go to the right and the 
 left, we cannot simultaneously raise and lower the eves, we 
 cannot at the same time breathe in and out, we cannot at the 
 same time stretch out our hand and draw it back, in brief, only 
 an action has its antithesis — an idea never ; only an action can 
 
 1 'Grundziige der Psychologic, ' Vol. I., p. 554. 
 
REACTION TIME AND MOVEMENT. &5 
 
 never be performed unless an antagonistic movement is thereby 
 excluded ; while any psychophysical stimulus can in itself be 
 united with any other, no physiological reason can be found in 
 the very nature of such a stimulus which makes the suppression 
 of a coordinated sensory stimulus a necessity." The very 
 foundation of the action-theory is based upon this conception. 
 Sensations are lively and forcible when the sensory stimulus 
 finds no resistance along the path of its discharge. But whence 
 comes this resistance? From antagonistic motor centers. If 
 the sensory stimulus passes over into the paths leading to a 
 subcortical motor center, which is itself inhibited on account of 
 a stimulus proceeding from the antagonistic center, the motor 
 discharge meets with resistance. The reciprocal action of an- 
 tagonistic centers accounts for the continuous play of reinforcing 
 and inhibitory forces on the field of consciousness. 
 
 The action-theory is independent of any microscopical in- 
 vestigations in anatomy. It transcends them and rests upon an 
 altogether higher plane. If metaphysics is only well founded, 
 there can be no doubt that physiology and anatomy will, in 
 time, suit their facts to the theories. But the action-theory can, 
 with equal facility, fit into any of the more special hypotheses 
 of nerve action founded on physiological and anatomical facts. 
 As an example, the primitive conception of nerve action as a 
 flowing of currents in and out of reservoirs can be adapted to 
 this theory. And by doing so Dr. Miinsterberg brings out the 
 conceptions of the theory in a clear and tangible form. 
 
 According to this primitive conception of nerve action, " the 
 outgoing current from the reservoir of the cortical cells, which 
 flows towards the periphery through the axis cylinder, would 
 come to a standstill if the lower level towards which it flows 
 were full and had no outlet. But if the vent in the lower basin 
 is open, so that the current can flow in the path to the muscle, 
 then the stream can pour forth from the cortex. The opening 
 of outgoing pipes in the lower center at once brings about a 
 change in the upper reservoir. As long as the lower basin is 
 blocked there can be no current in the upper basin, no matter 
 how much fluid may pour into the upper reservoir from con- 
 ducting paths. And if it is precisely upon the current that the 
 
DO THOMAS V. MOORE. 
 
 turning of the psychical millwheel depends, then the mill stands 
 still when the lower basin is stopped up, and begins to rattle 
 away when the sluices are opened below. We must now ask 
 for but one more step — that each lower reservoir stand in an- 
 tagonistic union with a neighboring one, so that the opening of 
 the sluices in one automatically closes those in the other." 1 
 
 Besides mere vividness, an impression is characterized by 
 many other qualities, such as being desirable or undesirable, 
 familiar or unfamiliar, etc. Can the action-theory offer any 
 explanation of these ? It seems to find no difficulty in the way. 
 There is more than one path possible for the motor discharge. 
 In fact, there are innumerable possibilities. Just what discharge 
 shall correspond to any given stimulus, is dependent on a very 
 complex set of conditions of which we know almost nothing. 
 But variations in the path of discharge give rise to those differ- 
 ent characteristics which give the idea a certain shade of value 
 in consciousness (Wertnuance). 
 
 To sum up the theory in a few words : M Each element of 
 consciousness is coordinated with a transfer from stimulation to 
 discharge in the cortex, and in such a way that the quality of 
 the sensation depends on the spatial position of the path of 
 stimulation, the intensity of the sensation. on the strength of the 
 stimulus, the accompanying characteristics (Wertnuance) on 
 the spatial position of the path of discharge, and the vividness 
 of the sensation on the strength of the discharge." - 
 
 If the action-theory is to be of any service in psychoid 
 must give us an explanation of psychological phenomena. And 
 it seems t6 be applicable with special facility to the theory of 
 attention. " That remains unnoticed," says Professor Miinster- 
 berg, "for which an action is not prepared, till the strength of 
 the stimulus forces the act ; but on the contrary the attention 
 lavs hold of that for which the motor discharge is prepared. * 
 * * That which opposes and hinders attention according to the 
 action-theory is always and only what leads to antagonistic 
 actions. It is the reciprocal blocking of the canals of n: 
 ment which prevents the dissipation of attention." 3 If attention 
 
 1 Op. cit. } p. 542-543- 
 *Ofi. <-//., pp. 54S-549- 
 3 Op. fit., p. 550. 
 
REACTION TIME AND MOVEMENT. fy 
 
 passes over into apperception this means that the stimulus is able 
 to start up a more complex reaction than that which corre- 
 sponds to its own isolated activity. This is the foundation for 
 the distinction between apperception and perception. If our 
 mind fixes upon any object it means that a stimulus arouses a 
 certain type of action. 
 
 (b) Criticism of the Theory, 
 
 It seems probable that the experiments of this dissertation 
 may throw some light on the theory of attention just outlined. 
 In performing these experiments the idea to which the subject 
 had to attend was to make the quickest possible movement on 
 hearing a certain signal. If the signal comes when the subject 
 is inattentive this must mean, according to Professor Miinster- 
 berg, that a certain path of movement which belongs to this idea 
 is more or less blocked. What path of movement would this 
 be? It seems that the motor path concerned in the movement 
 of reaction — to which the idea corresponds — should be in great 
 measure concerned. We should then expect in a series of reac- 
 tions made under conditions favorable to attention that the 
 maximum speed of movement would be greater than in a series 
 where the attention is disturbed. For if the path of movement 
 were more or less blocked, the full motor discharge could not 
 pass along it, and the movement executed would necessarily be 
 slower. Of course the movement of reaction is not the motor 
 discharge which Professor Miinsterberg speaks of as being the 
 necessary condition for consciousness. 1 It comes as the result 
 of far more complicated conditions than those which result in a 
 motor discharge when an idea flashes into consciousness. But, 
 notwithstanding this fact, the motor discharge passes along 
 motor paths most likely to be followed by the discharges of 
 those conscious processes concerned in reaction. If the idea of 
 making a movement as quick as possible has any motor dis- 
 charge, the path of discharge should be in great measure that 
 concerned in making the movement. And if inattention blocks 
 this path of movement we should certainly expect that the 
 movement executed would be slower in consequence of the 
 greater resistance to the motor discharge. 
 
 l Cf. op. at., p. 539. 
 
68 THOMAS V. MOORE. 
 
 In answer to this line of argument it might be said that the 
 movement is executed only after the attention is focused, that 
 the delay in reaction time means a reopening of the proper motor 
 path, and that the movement then executed takes place as in a 
 normal experiment. But such an answer seems to suppose the 
 older theory of attention, which regards it as a kind of faculty, 
 on which the motor processes may depend, rather than that 
 attention depends on motor processes. When the inattentive 
 subject hears the signal, there is a flash of consciousness — 
 ' now's the time ' — and the movement is executed. That flash 
 of consciousness represents the focusing of the attention upon a 
 rather complicated idea — to make the movement at once and as 
 fast as possible. It was not the return of the more general idea 
 to be ready to make the movement as fast as possible, as soon 
 as the signal might be heard. It was a special determinate idea 
 on which the movement followed as a matter of necessity. 
 According to Professor Miinsterberg, the flash of this idea into 
 consciousness meant that a motor discharge had already taken 
 place, that a certain type of action had been aroused. It passed 
 along motor paths just as it happened to find them more or less 
 blocked by previous conditions. Would not this discharge pass 
 through the very subcortical centers and along the very paths 
 concerned in the movement of reaction? And would not the 
 movement of reaction be executed at the same time? And if 
 this be true, any resistance encountered along this path (which, 
 according to Professor Miinsterberg, corresponds to a disturbance 
 of the attention) will delay the reaction and lessen the speed of 
 movement. But under conditions which were unfavorable to 
 attention we found that the movement time was not lengthened, 
 though the reaction time was considerably slower. Nor did the 
 longer reactions correspond to the longer movements which 
 occurred within the small limits of variation in the movement 
 time. 
 
 It must be acknowledged, however, that the test we have 
 applied cannot be considered as final. Perhaps the criticism 
 must be considered as premature, for Professor Miii> g has 
 
 not yet made his theory sufficiently explicit. It still rests in the 
 shades of metaphysics, for it has not yet ventured forth inu 
 
REACTION TIME AND MOVEMENT. 69 
 
 broad day of experimental science. If it should do so in the 
 future it cannot yet be said in just what form it will appear. 
 
 But apart from this criticism suggested by the experiments, 
 there are other points which, having once opened the subject, 
 it may not be out of place to mention. 
 
 The first is a point of method. Dr. Miinsterberg would 
 place his theory far above all microscopical investigations. It 
 is not for him to conform his theory to the facts of anatomy and 
 physiology. Let the anatomists and physiologists be subject to 
 the theory. Put forward a theory and let others look about for 
 the facts to support it, seems to be the principle on which he has 
 proceeded. 1 
 
 Such a method refuses to take cognizance of the lesson 
 taught by the history of modern science. Descartes' vortex 
 theory to explain the motions of the planets was based on the 
 metaphysical speculations ; Newton's theory of gravitation was 
 built upon calculations made from carefully observed facts. 
 The former is now an historical curio, the latter still forms the 
 basis of all astronomical calculation. This is but one instance 
 of many which could be adduced as examples of the success of 
 the inductive method of investigation, where speculation has 
 failed. Can Professor Miinsterberg boast of such special pow- 
 ers of penetration that he can afford to neglect the lesson taught 
 by the discoveries of modern science? It must not be supposed, 
 however, that I absolutely deny the value of metaphysical in- 
 quiry. It has its own field, and there purely inductive reason- 
 ing may be of little or no worth. But whenever facts are forth- 
 coming, these must serve as the basis of speculation. And a 
 theory which deals with subcortical motor centers, afferent and 
 efferent paths, cortical and spinal cells, cannot plume itself 
 upon being above the domain of facts, but must yield place to 
 them and not go further than they allow. 
 
 The next point of criticism may seem to be one of mere 
 words. But in speaking of the cortical motor discharge, Pro- 
 fessor Miinsterberg uses terminology which is more than tech- 
 nically at fault. It seems to be the expression of fanciful and 
 improbable ideas. " Now physiology," he says, " gives us the 
 
 1 Cf. op. cit, p. 406, p. 530, p. 540. 
 
7© THOMAS V. MOORE. 
 
 further information that the cortex does not send its impulse 
 directly to the peripheral muscles, but first acts upon subcortical 
 centers, which in their turn send the impulse down to medullary 
 ganglia. " ! What these subcortical centers are, or where they 
 are situated he does not say. On the next page he seems to 
 locate the medullary ganglia in the anterior horn of the spinal 
 cord. From this it would seem that Professor Miinsterberg 
 divides the path for conduction of motor impulses into three 
 stages, viz., (i) from the cortex to subcortical center; (2) from 
 the subcortical center to the root-cells in the anterior horn of the 
 spinal column ; (3) from these root-cells to the muscle. He 
 gives special prominence to the subcortical centers when a little 
 later on he says that, * the cerebral cortex, from which alone 
 psychophysical stimuli flow forth, must work upon subcortical 
 centers to discharge motor impulses.' 2 This statement, how- 
 ever, is untenable. According to all anatomists the fibres of 
 the pyramidal tract pass directly from the Rolandic area down 
 through the inner capsule to the crura and (omitting for the 
 sake of simplicity the cranial nerves) thence through the medulla 
 oblongata to the spinal cord, terminating in various places along 
 its entire extent. Perhaps the term center could be applied to 
 a nucleus. There are several nuclei and, if you will, centers 
 in the afferent paths. But the pyramidal tracts, either direct 
 or crossed, are nowhere interrupted by nuclei. Nowhere along 
 either of these tracts is there a motor center on which the 
 cortex must act in executing a movement. There is most prob- 
 ably another path which the cortex may employ in executing a 
 movement, and this path does involve a subcortical motor center. 
 It seems to be very well established that there is a much more 
 complex motor path from the cortex to the pons, from the pons 
 to the cerebellum and thence downward to the anterior root> 
 the antero-lateral descending tract. 3 But just what its function 
 is cannot be said. But that the primary path of motor impulses 
 is the pyramidal tract is the general position of anatomists and 
 physiologists. And this path is certainly not interrupted by any 
 subcortical motor centers. 
 
 l Op. tit., p. 532. 
 
 * Op. tit.,?. 533. 
 
 3 Cf. Van Gehuchten, ' Anatomie du Systetr.e nerveux de l'Homme 
 II., pp. 445-461. 
 
REACTION TIME AND MOVEMENT. 7 1 
 
 Starting from the supposition that there are subcortical motor 
 centers along the path of movement, Professor Miinsterberg 
 supposes two kinds whose action is reciprocal. One is bound 
 to the other as to an antagonistic center, so that the stimulation 
 of one subcortical center calls forth at the same time an inhibi- 
 tion of the antagonistic center. In support of this view he cites 
 the experiments of Dr. Sherrington on the reciprocal action of 
 antagonistic muscles. Dr. Sherrington has shown that for some 
 muscles, and under certain conditions, a contraction of the exten- 
 sors is accompanied by a relaxation of the flexors and vice versa. 
 But Dr. Sherrington does not localize the centers for reciprocal 
 action. He certainly does not postulate any subcortical center 
 on which the cortex must act — thereby inhibiting one antago- 
 nistic center — and so executing the movement. Dr. Sherring- 
 ton enumerated l the places of excitation where the phenomenon 
 of innervation could be elicited. These were : 
 
 i. "The skin and skin nerves (with ' decerebrate rigid- 
 
 ity')s 
 
 2. The muscles and the afferent nerves of muscle (with 
 
 1 decerebrate rigidity ') ; 
 
 3. The dorsal (posterior) columns of the cord (with 
 
 * decerebrate rigidity ') ; 
 
 4. Of the cerebellum (with ' decerebrate rigidity ') ; 
 
 5. Of the crusta cerebri (with ■ decerebrate rigidity'); 
 
 6. Of the internal capsules ; 
 
 7. Of the optic radiations; 
 
 8. Of the Rolandic cortex; 
 
 9. Of the occipital (visual) cortex." 
 
 But in all this there is no warrant for the conception of Dr. 
 Miinsterberg, that the cortex acts upon subcortical centers recip- 
 rocally connected, that one of these is inhibited and the antago- 
 nistic muscles relaxed, and the other discharges the root-cells 
 of a set of muscles which contract. The fact that under cer- 
 tain conditions the phenomenon is called forth by excitation of 
 the skin and skin nerves, afferent nerves of the muscles, and 
 the dorsal columns of the cord, would indicate that ' reciprocal 
 innervation ' is of a reflex character, taking place perhaps at 
 
 1 Proc. of the Royal Society of London, Vol. LXIL, p. 187. 
 
7 2 THOMAS V. MOORE. 
 
 various places along the spinal cord or in the bulb and due to 
 afferent impulses from the contracting muscles. Professor 
 Miinsterberg's postulation of reciprocal subcortical motor cen- 
 ters, which divide the pyramidal tract into two portions, is super- 
 fluous and contrary to the facts known to anatomical science. 
 
 4. The Motor Center Employed in the Process of 
 
 Reaction. 
 Another point on which the results of these experiments 
 bear is the question concerning the motor center employed in 
 the process of reaction. This has been the result of no little 
 theorizing. It originated before the distinction between sensory 
 and muscular reactions was brought out. In an article pub- 
 lished in Philosofhischc Studicn ' in 1886, Cattell put forward 
 the view that with practised subjects a reaction was probably 
 carried on without aid of the cortex. He wrote as follows : 
 " In the same way a reaction such as we are considering can 
 probably be made without need of the cortex, that is, without 
 perception or willing. When a subject has had no practice in 
 making reactions ( in which case the reaction time is usually 
 longer than 150 a) I think the will-time precedes the occur- 
 rence of the stimulus. That is, the subject by a voluntary 
 effort, the time taken up by which could be determined, puts 
 the lines of communication between the center for simple sen- 
 sations (in the optic thalami probably) and the center for the 
 coordination of motions (in the corf or a striata, perhaps, con- 
 nected with the cerebellum), as well as the latter center, in a 
 state of unstable equilibrium. When, therefore, a nervous im- 
 pulse reaches the thalami, it causes brain changes in two direc- 
 tions ; an impulse moves aiong the cortex, and calls forth there 
 a perception corresponding to the stimulus, while at the same 
 time an impulse follows a line of small resistance to the center 
 for the coordination of motions, and the proper nervous impulse, 
 already prepared and waiting for the signal, is sent from the 
 center to the muscle of the hand. When the reaction has often 
 been made, the entire cerebral process becomes automatic, the 
 impulse of itself takes the well-traveled way to the motor cen- 
 ter and releases the motor impulse.*' 
 
 l Vol. III., p. 322. Cf. also . Vol. XI., p. : 
 
 1 Mind, he. ci 
 
REACTION TIME AND MOVEMENT. 73 
 
 When Ludwig Lange, in 1888, published his article on the 
 two kinds of reaction, he put forward the hypothesis that the 
 motor center for muscular reaction is located in the cerebellum. 
 It did not seem to him possible that there should be a special 
 act of will involved in the actual process of muscular reaction, 
 because the subject is not conscious of any new voluntary im- 
 pulse in responding to the given stimulus. He looked upon the 
 muscular reaction as a brain reflex which differs from the reflex 
 actions of lower centers solely because it requires a preceding 
 stimulus of the will to make the necessary preparation for exe- 
 cuting the movement. This idea he made more explicit by 
 further details. The will causes to be stored up in the subcor- 
 tical center a certain amount of potential energy, which is held 
 there in unstable equilibrium. A sensory stimulus coming into 
 this center disturbs the equilibrium, and the energy thus set free 
 flows over along motor paths to the muscle and is there mani- 
 fested in the executed movement. This hypothesis can account 
 for the previous tension of the muscles, the fact that muscular 
 reactions are frequently made in response to the wrong stimulus, 
 and certain other phenomena which accompany the shorter form 
 of reaction. 
 
 But on what anatomical grounds can it be stated that the 
 cerebellum is the subcortical center for muscular reaction? 
 " As far as the cerebellum is concerned there is indeed estab- 
 lished with anatomical certainty only — 
 
 (a) The immediate connection with the sensory fibres of the 
 direct cerebellar tract ; this would give sufficient room for con- 
 duction from the organs of touch ; 
 
 (b) Connection with the motor regions of the cortex (Klein- 
 hirnbruckenbahn), i, e., with the center of voluntary muscular 
 innervation ; 
 
 (c) Connection with the sensory region of the cerebral cortex 
 (Kleinhirn-Grosshirnbahn), i. e. , with the central sensory surf aces. 
 
 There can be added as very probable : 
 
 (d) A motor path to the spinal column. In this would be 
 had the requisite connection with the group of reacting muscles. 
 
 In order to refer to the cerebellum muscular reactions for all 
 the domains of sense, over and above these connections, there 
 must be supposed : 
 
74 THOMAS V. MOORE. 
 
 (e) A sensory connection between the cerebellum and the 
 optic nerve. 
 
 (_/") A similar connection with the acoustic nerve. 
 
 Both these conducting paths are probably present, according 
 to what is now supposed concerning the functions of the cere- 
 bellum." 1 
 
 What Cattell thought was an analysis of the central proc- 
 esses of reaction in general, Lange claimed could be applied 
 to the muscular form of reaction alone. He saw no reason 
 to depart from Wundt's analysis of reaction when applied to the 
 sensorial form. 
 
 Dr. Sigmund Exner, in his ■ Psychische Erscheinungen,' 2 
 after referring to this view of Lange's, says : " There can be no 
 doubt that this form of a subtle voluntary movement is to be 
 referred to this, that the intention of the will to execute a special 
 movement as quickly as possible in response to the given stimu- 
 lus, rests upon a change which occurrences in the cortex call 
 forth in the conditions of irritability in the subcortical centers. 
 The condition thus brought about, which arises voluntarily, then 
 occasions without a new conscious act that the entrance of a 
 stimulus should produce a movement." Though Dr. Exner here 
 commits himself to the position that the muscular form of reaction 
 is carried on by a subcortical motor center, he does not specify 
 any particular center. 
 
 In reference to Lange's position, Wundt writes : " Ludwig 
 Lange has put forward the conjecture that the transmission of 
 the sensory into a motor discharge within the cerebral cortex 
 takes place only in the sensorial reaction ; in the muscular reac- 
 tion, however, it takes place in a lower center, probably in the 
 cerebellum, or possibly in the ganglia of the midbrain. I do 
 not believe that the arguments brought forward for this position 
 are convincing, or that they even make the hypothesis advanced 
 probable. Lange was certainly right if he held it was exceed- 
 ingly probable that in muscular reaction the transfer takes place 
 in a lower center, or that, at any rate, factors are wanting in it 
 which in the sensorial reaction proceed from a higher center, 
 standing in close relationship with the impulses of the will. 
 
 ^Philosophischc Studio:, Vol. IV., pp. 517-51& 
 2 P. 158. 
 
REACTION TIME AND MOVEMENT. 75 
 
 But doubtless there are centers of different order in the cerebral 
 cortex. If the muscular reaction takes place almost at the 
 same time as the entrance of the sensation, then there is nothing 
 in the way of supposing that the transfer takes place where the 
 conscious sensation is discharged — in the primary sensory cen- 
 ters of the cerebral cortex. The delay present in sensorial re- 
 actions which prevents erroneous reactions, very early appeared 
 to me to call for the hypothesis of an inhibitory action proceed- 
 ing from an apperception center, which lasted until the stimula- 
 tion (Signalreiz) belonging to this center caused a partial dis- 
 charge of it. It also seems to me that the presence of transi- 
 tional forms can best be harmonized with this view. For it is 
 easy to understand that such an inhibition can be more or less 
 active ; but it is very difficult to see that between a reflex dis- 
 charge, merely in a subcortical center, and a function of the 
 cerebral cortex, such transitional values could be present. "' 
 
 The evidence from our experiments seems to point to the 
 conclusion that the centers for muscular reaction are not so 
 widely separated as the cerebral cortex and the cerebellum. On 
 the hypothesis that there is a distinction between sensorial and 
 muscular reactions, it is quite clear that those made without a 
 preparatory signal were sensorial reactions. For leaving the 
 subject without a preparatory signal makes it impossible for him 
 to attend primarily to the movement. He must be straining his 
 attention to catch the sound of the reaction stimulus. On the 
 other hand, the reactions made by the subjects when the pre- 
 paratory signal was given were, as we have said, mainly of the 
 muscular form. This was particularly true of Subject B. But 
 we found no decided difference between the speeds of move- 
 ment in the two cases. Perhaps the speed of movement in the 
 reactions without preparatory signal was a little quicker than in 
 the muscular reactions. But this was not constantly the case, 
 and was probably due to the factors already mentioned. 
 
 Then, again, we compared the speed of the movement 
 which came as the result of a voluntary choice with that which 
 followed upon a reaction. In the experiments by which this 
 
 i'Grundziige der physiologischen Psychologies 4th ed., II., p. 317. Cf. 
 also 5th ed., III., p. 428. 
 
76 THOMAS V. MOORE. 
 
 comparison was made the subjects probably reacted in the 
 muscular manner. But there was no decided difference in time 
 between the voluntary movement and the movement of reaction. 
 It will be generally conceded that the motor center for the 
 voluntary movement and the sensorial reaction is situated in the 
 cortex. And at the same time Lange's conception of the proc- 
 ess of muscular reaction cannot be shown to be impossible, 
 even after the great advances made in the anatomy of the nerv- 
 ous system since 1888. But if we suppose that the center for 
 muscular reaction is subcortical, it would seem likely that the 
 line of movement executed by the center would differ from that 
 of the movement executed by the cerebral cortex — and for two 
 reasons. In the first place, if a subcortical center is reflexly 
 discharged by the incoming stimulus in a muscular reaction, it 
 is probable that the intensity of this discharge would be different 
 from that of a discharge coming from the motor area of the 
 cortex. The root-cells in the spinal cord would therefore be 
 discharged with different force in each case and the subsequent 
 movements would differ in speed. And in the second place, 
 even though the normal maximum discharge of the cortical 
 cells and the subcortical center might happen to be equal, it is 
 still very unlikely that the discharges passing from the cortex 
 and subcortical center would be so equally distributed that the 
 final resultant which reached the root-cells of the spinal cord 
 would be the same in the two cases. The path from the cere- 
 bral cortex to the spinal root-cells is without interruption along 
 the fibers of the pyramidal tracts. If, for instance, the subcor- 
 tical center were the cerebellum, the sensory stimulus would 
 reach it through different nuclei along a different path, and 
 then when the motor cells of the cerebellum were discharged 
 the impulse would not pass to the root-cells by the pyramidal 
 tract, but probably by the antero-lateral descending tr. 
 Different connections would have to be made in the grey matter 
 of the spinal cord from those used by the pyramidal tract. 
 Such a difference in the path of movement would probably re- 
 sult in a very different distribution of the motor discharg 
 which would be manifested in the record of the movement time. 
 Not finding evidence of such a difference, we conclude that the 
 
REACTION TIME AND MOVEMENT. 77 
 
 center for the different kinds of movement cannot be so widely 
 separated as the cortex and a subcortical center. It seems 
 most reasonable to suppose that the motor cells concerned are 
 those of the Rolandic area. 
 
 5. The Distinction between Muscular and Sensorial 
 
 Reactions. 
 
 Now something must be said of the validity of the distinction 
 between muscular and sensorial reactions. On this point there 
 are two very opposite opinions. That of the Wundtian school 
 may be expressed in Wundt's own words : " Um moglichst voll- 
 standige Reactionszeiten zu erhalten, muss die Aufmerksamkeit 
 intensiv auf den erwarteten Sinneseindruck gerichtet werden, 
 wobei sich die Spannung der Aufmerksamkeit immer zugleich 
 durch Muskelempfindungen des betreffenden Sinnesgebiets, z. 
 B., in den Accommodations -und Augenmuskeln dem Tensor- 
 tympani verrath ; dagegen darf sich die Aufmerksamkeit nicht 
 aus das reagirende Bewegungsorgan richten, und das zuver- 
 lassige Kriterium fur die Erfiillung dieser Bedingung liegt 
 darin, dass die Muskelspannungen dieses Organs unmerklich 
 sind. Will man dagegen einen extrem verkiirzten Reactions- 
 vorgang erhalten, so ist es nothig die Aufmerksamkeit aus- 
 schliesslich auf das reagirende Organ zu verrichten, was immer 
 mit einer intensiveren Muskelspannung desselben verbunden 
 ist." " 
 
 The ground for the distinction, according to Wundt and his 
 school, is the manner of directing the attention. All subjects 
 who can at will place the strain of attention in the afferent or 
 efferent circuit will be able to react either sensorially or muscu- 
 larly. 
 
 Professor Baldwin, however, in propounding the type- 
 theory of simple reaction sought another ground for the dis- 
 tinction. According to him, the root of the distinction lies in 
 individual differences of the subjects. <( We find," he says, 
 " cases of relatively shorter sensory times similar to mine 
 
 1 ' Grundziige der physiologischen Psychologie,' II., p. 309 (4th ed.). Cf. 
 also a somewhat different expression of the distinction in the 5th ed., III., p. 
 412 ff. 
 
7§ THOMAS V. MOORE. 
 
 reported (for electrical stimulus) by Cattell, and (for sound 
 stimulus) by Flournoy. We may accordingly say that such 
 individual differences are clearly established, and must here- 
 after be acknowledged and accounted for in any adequate theory 
 of reaction. The attempt of Wundt, Kiilpe, and others to rule 
 these results out, on the ground of incompetency of the reagents, 
 is in my opinion a flagrant argumentum in circulo. Their con- 
 tention is that a certain mental An/age or aptitude is necessary 
 in order to experimentation on reaction times. And when we 
 ask what the Anlage is, we are told that the only indication of 
 it is the ability of the reagent to turn out reactions which give 
 the distinction between motor and sensory time which Wundt 
 and his followers consider the proper one. In other words, 
 only certain cases prove their result, and these cases are selected 
 because they prove that result. It is easy to see that this manner 
 of procedure is subversive both of scientific method and of safely 
 acquired results in individual psychology. For the question 
 comes: What of these very differences of individual Ami 
 How did they arise ; what do they mean? Why do they give 
 different reaction time results? To neglect these questions and 
 rule out all Anlagcn but one, is to get the psychology of some 
 individuals and force it upon others and thus to make the r 
 tion method of investigation simply the handmaid to dogma.'" ' 
 " The individual differences in reaction arise from the fact 
 that there is a natural and permanent tendency in all people to 
 take the same cue for their movements that they do in speech. 
 The doctrine of * types ' rests upon certain facts which may be 
 briefly summed up. A voluntary motor performance — say 
 speech — depends in each particular exercise of it upon the pos- 
 sibility of getting clearly in mind {mtcrieur t innerlicJi) some 
 mental picture, image, presentation, which has come to stand 
 for or represent the particular movements involved. This 
 mental ' cue ' or representation may belong to either of two great 
 classes : it may be a ' sensory ' cue or a 4 motor ' cue. People 
 are of the sensory type, or of the motor type for speech, accord- 
 ing as their cue in speech is sensory or motor, that is, according 
 
 1 'Types of Reaction,' J. Mark Baldwin (and W, J. Shaw\ Psychology 
 Re view, 1S95, II., p. 265. 
 
REACTION TIME AND MOVEMENT. 79 
 
 as in speaking they think of the sounds of the words as heard, 
 the looks of the words as written, etc. — the cues furnished by 
 the special senses associated habitually with speech — this on 
 the one hand ; or according as, on the other hand, they think 
 of or have in mind the movements of the vocal organs, lips, 
 tongue, etc., involved in speech." 1 " So in simple hand move- 
 ments people may show the sensory and motor types. This is 
 my hypothesis. The man, therefore, who gives relatively 
 shorter motor reactions is a * motor ' in his type ; with him the 
 thought of movement is the most facile beginning of the move- 
 ment, just because it is really the movement and nothing else 
 that he thinks of. That is his Anlage. But the man who gives 
 relatively shorter sensory (auditory, visual) reactions is a ' sen- 
 sory ' in his type ; with him the attempt to think of the move- 
 ment as a movement interferes with the prompt and exact exe- 
 cution of it, just because he is not accustomed to execute his 
 movements in that way. That is his Anlage" 2 
 
 It would be out of place in our present paper to criticise ex- 
 tensively either of these theories of reaction, since we have made 
 no special test concerning them. But it does seem incumbent 
 upon us to state what was meant in the course of the paper 
 when the terms sensory and muscular reaction were used. 
 
 We have supposed with Wundt and his school that when the 
 strain of attention (Spannung) is really in the efferent circuit 
 all subjects will react more quickly than when the strain of 
 attention is in the afferent circuit. But the attention here re- 
 quired is of the nature of tension, or what the Germans call 
 Spannung. Only secondarily is it a visualization of the move- 
 ment or of the signal. However, Professor Baldwin's experi- 
 ments do present a real difficulty to this position, and it would 
 not be fair to ignore them or arbitrarily rule them out of court. 
 They are facts, and as such they must be accounted for. But 
 their ultimate explanation may not be in the theory of types as 
 expounded by Professor Baldwin. Some subjects find it hard 
 to direct their attention to the movement, and others find diffi- 
 culty in directing their attention to the signal. Perhaps the 
 
 x Loc. cit. } p. 268. 
 2 Loc. cit.y pp. 269-270. 
 
80 THOMAS V. MOORE. 
 
 reason for this is to be sought in the fact that some are in the 
 habit of attending to sensory images and others to motor images. 
 But when a subject who is really of the motor type tries to react 
 sensorially and gives a short reaction, he may indeed picture to 
 himself a sound or a light, but it might be said that the attention 
 or Spannung was not primarily in the afferent, but as a matter 
 of fact in the efferent circuit. But at the same time, if he com- 
 menced to think about the movement, to try to see it or feel it, 
 what was before carried on automatically might be interfered 
 with by being consciously attended to. Tension would be drawn 
 away from the muscles, to be given to visualizing the movement. 
 In every reaction there are two mental images which fluctuate 
 more or less in consciousness while the subject is waiting to 
 react. One is the sensory representation of the signal ; the other 
 is the motor (or perhaps visual) representation of the movement. 
 But while this fluctuation of mental images is going on there is 
 not a simultaneous changing of the center of neural tension. 
 Too little attention has been given to this distinction — between 
 Spannung and Aufmerksamkeit — in previous discussions of 
 the problem. Perhaps a better understanding of the distinction 
 might show that the two theories are really closer together than 
 they seem to be at present. 
 
BIBLIOGRAPHY. 
 
 General Works. 
 
 Lewellys F. Barker, The Nervous System and Its Constituent 
 
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 Sigmund Exner, Entwurf zu einer physiologischen Erklarung der 
 
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 Warren P. Lombard, General Physiology of Muscle and Nerve, 
 
 An American Text Book of Physiology, pp. 32-151, Philadel- 
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 Wilhelm Wundt, Mechanik der Nerven und Nervencentren, Erste 
 
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 Physiology of Processes Concerned in a Voluntary 
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 (81) 
 
82 THOMAS V. MOORE. 
 
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 J. Berry Haycraft, Voluntary and Reflex Muscular Contractions, 
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 E. Hitzig, Hughlings Jackson and the Cortical Motor Centers, Brain, 
 
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 Further Experimental Note on the Correlation of Action of 
 
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 On Reciprocal Innervation of Antagonistic Muscles, Third 
 
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 Antagonistic Muscles and Reciprocal Innervation, Fourth 
 
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 Literature on Reaction Time. 
 
 For accounts of the literature on Reaction Time, cf. the follow- 
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 Nicolaus Alechsieff, Reactionszeiten bei Durchgangsbeobach- 
 
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REACTION TIME AND MOVEMENT. 83 
 
 E. Kraepelin, Ueber die Beeinflussung einfacher psychischer Vor- 
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 J. McKeen Cattell, On Reaction Times and the Velocity of the 
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 J. M. Baldwin, The < Type-Theory ' of Reaction, Mind, N. S., 
 1896, V., pp. 81-90. 
 
 W. G. Smith, Antagonistic Reactions, Mind, Jan., 1903, pp. 47-58. 
 
 E. B. Titchener, The 4 Type-Theory ' of Simple Reactions, Mind, 
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 The Force and Rapidity of Movements. 
 
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 E. B. Delabarre, R. R. Logan and A. Z. Reid, The Force and 
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 A. Cleghorn, The Inhibition Time of a Voluntary Muscular Con- 
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 Charles Fere, L'energie et la vitesse de mouvements volontaires, 
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 Note sur l'energie et la vitesse des divers mouvements des mem- 
 
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 3I3-3H. 
 
 Le travail et le temps de reaction, Comptes rendus de la Soc. 
 
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 J. B. Haycraft, Upon the Production of Rapid Voluntary Move- 
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 Wm. R. Jack, On the Analysis of Voluntary Movements by Certain 
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84 THOMAS V. MOORE. 
 
 J. Orschansky, Zur Lehre von der Willensthatigkeit, Archiv fur 
 
 Physiologies 1889, pp. 173-198. 
 E. W. Scripture and Jno. M. Moore, A New Reaction-Key and 
 
 the Time of Voluntary Movement, Studies of Tale Psy. Lab., 
 
 I., 1892-3, pp. 88-91. 
 
 Reinforcement and Inhibition of Movement. 
 
 Dr. De Boeck et Is. Gunzburg, De l'influence de l'alcool sur le 
 travail du muscle fatigue, Bull, de la Societe de Medecine men- 
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 N. Bubnoff und R. Heidenhain, Ueber Erregungs- und Hem- 
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 J. Claviere, Le travail intellectuel dans ses rapports avec la force 
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 A. Cleghorn, The Reinforcement of Voluntary Muscular Contrac- 
 tions, Am. Journal of Physiology, 189S, I., pp. 336-345. 
 
 C. Collucci, L'Ergografo nelle ricerche di psico-fisiologia, Annali 
 di Nevrologia, 1899, XVII., 205-294. 
 
 S. Exner, Zur Kenntniss von der Wechselwirkung der Erregungen 
 im Centralnervensystem, Archiv fur die ges. Physiologie, 
 XXVIII. , pp. 487-506. 
 
 Charles Fere, Etudes experimentales de l'influence des excitations 
 agreahle et des excitations desagreable sur le travail, L'Annee 
 Psy., 1900 (1901), VII., pp. S2-129. 
 
 Etudes experimentales sur le travail chez l'homme et sur quel- 
 
 ques conditions qui influent sur sa valeur, Journal de I Anat. et 
 de la Physiologie, 1901, XXXVII. , 1-79. 
 
 L'excitabilite comparee des deux hemispheres cerebraux chez 
 
 l'homme, L'Annee Psy., 1900 (1901), VII.. pp. 30-142. 
 
 L'influence de l'alcool et du tabac sur le travail. Archives de 
 
 Neurologic, 1901, XII., 369-3S4, 463-475. 
 
 L'influence du bouillon sur le travail, Comptes rcndus So: 
 
 Biologie, 1900, p. S29. 
 
 De l'influence de Techauffement artificiel de la tete sur le 
 
 travail, Journal dc I Anatomie et de la PhysimUgmy 1900, 
 XXXVII. , pp. 291-30S. 
 
 L'influence de quelques excitations deplaisantes sur le 
 
 Comptes rend us Soc. dc Biologic, 1900, p. 10S 
 
REACTION TIME AND MOVEMENT. &5 
 
 Note sur Taction excitante de l'antipyrine, Journal de Neurolo~ 
 
 gie, 1901, VI., pp. 631-634. 
 
 Note sur l'influence reciproque du travail physique et du travail 
 
 intellectuel, Journal de VAnat. et de la Physiologie, 1901, 
 XXXVII, pp. 625-637. 
 
 Notes sur la rapidite des effets des excitations sensorielles sur 
 
 le travail, Comptes rendus Soc. de Biologie, 1900, p. 845. 
 
 L'influence sur le travail d'un muscle de Tactivite d'autres mus- 
 cles, JVouv. Icon. Salpetriere, 1901, XIV., pp. 432-461. 
 
 La pathologie des emotions, Ch. III., Paris, 1892. 
 
 Recherches experimentales sur la fatigue par des excitations de 
 
 l'odorat, Nouv. Icon. Salpetriere, 1901, XIV., pp. 327-353. 
 
 Sensation et Mouvement, 1st ed., Paris, 1887; 2d ed., 1901. 
 
 Travail alternatif des deux mains, L'Annee psychoid 1900 
 
 (1901), VII., pp. 130-142. 
 
 Les variations de l'excitabilite dans la fatigue, UAnnee psy- 
 choid 1900 (1901), VII., pp. 69-81. 
 
 Aug. Forel, Lahmt der Alkohol die Muskelleistung oder fordert er 
 sie? Correspondenz-Blatt filr Schweizer Aerzte, 1897, XXVII. , 
 p. 672. 
 
 Hermann Frey, Ueber den Einfluss des Alkohols auf die Muskeler- 
 
 miidung, Mitth. aus klin. und med. Instituten der Schweiz, 
 
 1896, IV., H. i., pp. 1-47. 
 A. Freusberg, Ueber Erregung und Hemmung der Thatigkeit der 
 
 nervosen Centralorgane, Archiv fur die ges. Physiologie, X., 
 
 pp. 174-208. 
 J. G. Gonzalez, The Study of Inhibition, N. Y. Med. /., 1901, 
 
 LXXI, pp. 116-117. 
 Vaughan Harley, Sugar as a Food in the Production of Muscular 
 
 Work, Proc. of the Roy. Soc. Lond., 1903, LIV., p. 480. 
 
 The Value of Sugar and the Effect of Smoking on Muscular 
 
 Work, Journal of Physiology, 1894, XVI., p. 97. 
 
 R. Heidenhain, Ueber Erregung und Hemmung, Arch, filr die 
 ges. Physiologie, XXVI., pp. 546-557. 
 
 H. E. Hering und C. S. Sherrington, Ueber Hemmung der Con- 
 traction willkurlicher Muskeln bei elektrischer Reizung der 
 Grosshirnrinde, Archiv filr die ges. Physiologie, LXVIIL, pp. 
 222-228. 
 
86 THOMAS V MOORE. 
 
 Ludwig Hofbauer, Interferenz zwischen verschiedenen Impulsen im 
 Centralnervensystem, Archiv fur die ges. Physiologie, LXVILL, 
 pp. 546-595- 
 
 Kronecker et Cutter, Effets du travail de certains groupes muscu- 
 laires sur d'autres groupes qui ne font aucun travail, Comptes 
 rendus, Acad, de Med., 1900, CXXXI., p. 492. 
 
 Warren P. Lombard, Some Influences which Affect the Power of 
 Voluntary Muscular Contraction, Journal of Physiology, 1892, 
 XIII., p. 44. 
 
 Arnaldo Maggiora, De Taction physiologique du massage sur les 
 muscles de Thomme, Arch. Ital. de Biologie, 1S91, XVI, p. 225. 
 
 Ugolino Mosso, Action physiologique de la cocaine, etc., Arch. 
 Ital. de Biologie, 1S91, XIV., p. 247. 
 
 M. Sternberg, Die Sehnenreflexe und ihre Bedeutung fur die 
 Pathologie des Nervensystems, 1 Wien, 1S93. 
 
 Max Verworn, Zur Physiologie der nervosen Hemmungserschein- 
 ungen, Archiv fur Physiologie, 1900 (Suppl. Bd.), pp. 105-123. 
 
 Guy M. Whipple, The Influence of Forced Respiration on Psychical 
 and Physical Activity, Am. Journal of Psychology, 1S97-S, IX., 
 pp. 560-571. 
 
 M. Brown-Sequard, Champ de Taction de Tinhibition, Archives de 
 Physiologie normal et pat hologique, iSSS, pp. 1-23. 
 
 Augustus D. Waller, On the Inhibition of Voluntary and Elec- 
 trically Executed Muscular Contraction by Peripheral Excitation, 
 Brain, XV., 1S92, pp. 35-64. 
 
 1 The literature which bears on the stimuli which affect the knee-jerk should 
 be considered here. Most of it will be found in the bibliography appended to 
 Dr. Sternberg's monograph, which contains over eight hundred references. 
 
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