REPRINTED FROM 
Vol. II. No. 1. 
January, 1895 
THE 
Psychological Review 
EDITED BY 
J. MARK BALDWIN 
Princeton University 
And 
J. McKEEN CATTELL 
Columrta College 
WITH THE CO-OPERA TIOS OF 
ALFRED BINET, £coLe des Hautes-Etudes, Paris; JOIJN DEWEY, University of 
Chicago; H. H. DONALDSON, University of Chicago; G. S. FULLERTON, 
University of Pennsylvania ; WILLIAM JAMES, Harvard Universitv ; 
JOSEPH JASTROW, University of Wisconsin; G. T. LADD, Yale 
Univf,rsiiy; HUGO MUN8TERBERG, Harvard University; 
M. ALLEN STARR, College of Physicians and Surgeons, 
New York; CARL STUMPF, University, Berlin; 
and JAMES SULLY, University College, 
London. 
CONTENTS. 
Hermann von Helmholtz and the New Psychology : C. STumpf. 
The Theory of Emotion (II.): The Significance of Emotions: John Dewey. 
The Muscular Sense and its Location in the Brain Cortex: M. Allen Starr. 
A Location Reaction Apparatus: G. W. Fitz. 
*'TJtseussw?T* 
Mind and Body: Paul Shorey ; Attention as Intensifying Sensation: 
H. M. Stanley; Pleasure-Pain and Emotion: H. R. Marshall; 
A Comment: E. B. Titchener. 
Psychological Literature: 
Hallucination and Telepathy (Parish's Ueher die Trugwahrnehmungen, Pod- 
more' s Apparitions and Zbought-Transference, Sidgwick's Report on Census 
of Hallucinations'): William James; Ethical (Seth's Study of Ethical 
Prim Lies, Hodge's the Kantian Epistemology and Theism, Sharp's The 
AEsthetic Element in Morality): T. G. Hibben ; Neurology: H. H. D.‘; 
Vision (Oscillations in the Retinal Process, Color Blindness): C. Ladd 
Franklin; Taste: F. Kiesow; Experimental (Binet’s Psychologic des 
Grands Calculateurs, Travaux du Laboratoire de la Sorbonne): H. C. 
Warren ; Recognition and Association: M. W. Calkins ; Logic and 
Epistemology; J. H. Tuf*rs, G.S.F., A.B.; Anthropology and Child Psy- 
chology : D. G. Brinton, Earl Barnes. New Books. 
Notes. 
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Entered at the P< st-office at New York as Second-class Matter. 
Copyright, 1895, by Macmillan & Co. A LOCATION REACTION APPARATUS. 
BY PROFESSOR G. W. FITZ, 
Lawrence Scientific School, Harvard University. 
The problem which stimulated to the designing of this 
apparatus was that of testing the power of an individual to 
quickly and accurately touch an object suddenly disclosed to 
him in an unexpected position. In order to make the prob- 
lem as simple as possible the apparatus (see Figure i) 
was so devised that the subject is required to make a 
movement of the finger from the end of the nose to some 
portion of the arc of a circle of which he is the centre and 
whose plane is at the level of his elbow. Three positions 
were selected to give a wide range of movement, namely, 
the centre immediately in front and a point on each side at a 
distance of about 14 in. (A, B and C). The object to be touched 
•consists of a*white~«pot iZ-iu- which may be 
placed at any one of these points without the knowledge of 
the subject, a screen being in front, arranged to fall at the 
proper time and instantly disclose the spot. In connection 
with this, a pendulum chronoscope is used which measures 
the interval of time between the falling of the screen and the 
touching of the white spot. 
The apparatus for determining the error is constructed to 
measure the distance of the centre of the finger (Fig. 2, F) 
from the centre of the white spot (S) on either side, thus 
showing the error of the movement executed and its direc- 
tion. It consists of a horizontal strip (St) of blackened brass 
7 in. long, bearing in its centre the white spot (S). This is 
hinged along one side so that the finger pressure makes an 
electrical contact (E) to determine the end of the time inter- 
val and also releases the clamp controlling the error record- 
ing apparatus. Below this are two light arms (GG) pivoted 
37 38 
G. IV. FITZ. 
at a common point directly under the white spot, so that 
their tips project above the first strip about in. These 
arms are connected by a spring (Sp) tending to pull them to- 
gether, but are held apart in the preliminary position by the 
Fig. 1.—Location Apparatus. 
pressure of the clamp projecting downward from strip (St, 
not shown in diagram) and are released by the touch of the 
subject, springing instantly to grasp the finger (F) between 
them. The raising of the finger clamps them anew in this 
position, and the displacement of the index showing the mid 
point of the finger can be read on its scale (R-L). This is 
found to work very quickly and conveniently with practi- 
cally no observation error. A frame work carries the 
various parts and a set of wheels enables it to be run into any 
position desired. 
The chronoscop'e'has a balanced pendulum (Fig. 3), 12 
inches total length, so weighted (W) that the time of swing 
is about a second and a half. The pendulum (P) carries a 
Fig. 2.—Error Index. 
light index (I) that may be clamped instantly in any position 
on the scale (S), which latter was graduated empirically in 
hundredths of a second by a falling weight. The pendulum A LOCA TION REACTION APPARA TUS. 
39 
is held in the preparatory position (Fig. 4) by means of a hook 
(H) connected with the armature (A) of an electromagnet 
Fig. 3.—Pendulum Chronoscope. 
M). The breaking of the circuit by the fall of the screen) 
releases (Fig. 5, R) the pendulum carrying its index; the re- 
Fig. 4.—Pendulum and Index 
Clamp Release. 
Fig. 5.—Clamp Release, 
making of the circuit, by the touch of the subject’s finger, 
releases (Fig. 5, R) the clamp (C) and catches the index so that 40 
G. IV. FITZ. 
the time may be read upon the scale (Fig. 3, S). There is a 
level (L) upon the base board to enable one to put it in an 
exactly horizontal position, and the error of the instrument 
is thereby reduced to a negligible quantity. The details of 
the release are shown in Figures 4 and 5. 
By means of this apparatus it was hoped to measure some 
of the elements making up the differences which exist be- 
tween individuals in their power to do certain things requir- 
ing quickness and accuracy, as, for instance, tennis playing 
and fencing, the essential requirements being the perception 
and quick interpretation of external conditions, followed in- 
stantly by an appropriate motor response. The apparatus** 
gives us somewhat similar conditions to those offered by the 
games mentioned, but gives them so definitely that it is pos- 
sible to get a numerical statement of what each individual is 
able to do in terms of quickness and accuracy. The differ- 
ences have been found to be remarkably great, and there is 
an apparent lack of coordination between time and error; 
that is, those who are quick are not necessarily less accurate 
than those who are slower. 
The accompanying table shows the result of some work 
with the apparatus, and is given to suggest the wide range 
of individual ability thus tested. 
Time in 
Ttfir sec- 
No. 
Males. 
% of 
total. 
Av. 
error. 
No. 
Females. 
% of 
total. 
Av. 
error. 
27- 35 
11 
6.2 
11.1 
1 
1-5 
10. 
35- 45 
48 
22.5 
10.05 
12 
18. 
9.4 
45- 55 
54 
3i. 
8.25 
18 
26. 
7.8 
55- 65 
29 
l7 • 
9- 
25 
35- 
7.2 
65- 75 
18 
11. 
8.2 
11 
16. 
5-4 
l_n 
1 
00 
t_n 
8 
5- 
3-i 
4 
5- 
4.4 
85- 95 
4 
2. 
4.05 
0 
95-105 
0 
0. 
0 
1 
105-115 
1 
.6 
7.8 
The tests were made in three positions (A, B, C, in the 
order i, 2, 3, 4, 5, 6), as described, every individual making A LOCA TION REACTION APPARA TVS. 
41 
four attempts in each position, twelve all told. These were 
recorded separately, hence it is possible to study each effort 
in relation to the position in which it was made. This was 
done for both hands to compare the right with the left in 
regard to quickness, accuracy and direction of error; but it 
has been thought best not to include a discussion of the 
results from this standpoint in the present paper. 
The table contains a study of the observations made with 
the right, or preferred, hand by 173 males and 72 females, 
all those of one individual being treated here as if made in 
one position. They were obtained from several sources, a 
large portion of them being derived from the Psychological 
Laboratory of the Columbian Exposition, Chicago, where 
the apparatus was in use by Prof. Jastrow, and also from 
Harvard students and in the Harvard Summer School of 
Physical Training. Inasmuch as it did not seem possible to 
make a fair classification of these, they have been arranged 
in two divisions, male and female, regardless of ages and 
experiences. 
The first column of the table gives the limits of quickness, 
determining each group of these two classes: the second, in 
the two divisions of the table, gives the number of individu- 
als whose reactions lie between the limits noted: the third 
gives the percentage of this number to the total number in 
the class, while the fourth gives the average error which is 
a measure of the accuracy of the movements. It will be 
noticed that the number of individuals of the different groups 
shows a distinct distribution curve with the apex at about 
0.5 Sec. in the males and 0.6 Sec. in the females, suggesting 
that these are near the means. Of course, this quickness is 
made up of the reaction—time proper and the time occupied 
in making the movement from the end of the nose to the 
plane of the apparatus. It will be noticed also that the aver- 
age errors for these groups do not vary in ratio to the 
quickness, but that those who make the movement in .35 Sec. 
are almost as accurate as the group making the movement in 
.75 Sec., some being, indeed, more accurate in the former 
case than in the latter. There is a suggestion of uniformity 
in the value of the errors, and one cannot help thinking that 42 
G. IV. FITZ. 
the everyday, haphazard activity, demanding as it does a 
certain degree of accuracy in the execution of movements, 
determines for each individual his range of error, and that 
time is the main element of variation. 
It will be noted that though the time of the females is 
longer than that of the males, there is a compensatory in- 
crease in accuracy. The relation between time and accuracy 
has not been determined, so it is not possible to make a state- 
ment of the value of accuracy in terms of time, but un- 
doubtedly the individual, who is fairly accurate and very 
quick, is more accurate when he takes more time, yet it is 
also true that he is sometimes much more accurate than at 
others without being necessarily either quicker or slower. 
These individual variations have still to be studied. The 
main point to be emphasized now is, that between two per- 
sons it is practically possible to bring one element of the test, 
either time or accuracy, to equality, so that the difference 
may be expressed numerically in terms of the other. Just 
what value this series of tests has can not be stated posi- 
tively, but we believe it has distinct reference to motor abil- 
ity, and that this will be shown by an increased number of 
observations upon individuals whose powers are definitely 
known by comparison with others in the various games. 
I wish to acknowledge special indebtedness to Prof. Joseph 
Jastrow, Mr. G. W. Morehouse, Dr. F. B. Jewett and Mr. 
A. W. Jeardeau for assistance in getting observations.