[Reprinted from The Psychological Review, Vol. I, No. i, January, 1894.] 
WORK AT THE YALE LABORATORY. 
BY E. W. SCRIPTURE. 
The first year in the life of a laboratory is one of incredible 
difficulties and incessant labor in getting matters arranged. 
Nevertheless, we have been able to carry on several investiga- 
tions and bring them to successful conclusion and publication.* 
The most extensive investigation was that by C. B. Bliss 
on reaction-time and attention. The graphic method was 
developed so that records absolutely accurate to thousandths of 
* Studies from the Yale Psychological Laboratory, 1892-1893, edited by E. W. 
Scripture, New Haven, 1893. SHOR TER CONTRIBUTIONS. 
67 
a second can be made and counted with less trouble than 
chronoscope records. The vibrating line receives a spark- 
record at the instant of the stimulus and another at the instant 
of reaction. The single waves, .01 sec., are counted and the 
odd tenths obtained by the eye. The necessary arrange- 
ment of the currents led to the invention of a multiple key. 
The reaction-time to sound was measured with and with- 
out disturbances of attention. When the attention was dis- 
tracted by a steady light the disturbance of the reaction-time 
to sound was very small; with an unsteady, moving light it 
was very great. When the attention was disturbed by a steady 
sound, e.g., a tone, no disturbance resulted in the reaction to 
sound ; with an intermittent sound, e.g., a metronome, it was 
very marked. In making these experiments some unexpected 
results were obtained, showing that the reaction-time to a 
sound heard in both ears is shorter than when the sound is 
heard only in one ear, even after making allowance for the 
difference in intensity. 
Dr. Bliss made the attempt to determine the relation of 
changes in reaction-time to various other mental disturbances. 
After each set of experiments records were made of anything 
worth noting that had passed in the mind. The conclusions 
from these introspective observations are : 
1. Reaction-time is constantly affected by irregular dis- 
turbances a large part of which may be detected by intro- 
spection. 
2. Introspection is not to be trusted in estimating results. 
3. Reactions to the wrong signal, reactions before the 
signal is heard, and the reflex nature of reactions are not 
sufficient criteria to distinguish muscular from sensorial re- 
actions. 
4. There are at least six distinct kinds of voluntary atten- 
tion : ideational attention, neural attention, feeling attention, 
muscular attention, preparatory attention, and inattention. 
5. The involuntary attention is constantly changing. 
Experiments were made showing the influence of various 
distractions and mental operations on the rate of voluntary 
tapping and on the steadiness with which a lever could be 
kept at a given place. 68 
E. IV. SCRIPT URE. 
C. E. Seashore succeeded in making the first trustworthy 
measurements on the time required for altering the accom- 
modation of the eye. He has established three important 
principles: 
i. Within certain limits the accommodation-time varies 
with the distance between the points for which the eye is to be 
accommodated. 
2. It takes longer to change the accommodation from near 
to far than from far to near, and this difference in time varies 
directly with the length of the accommodation-time. 
3. For equal distances in the same range the accommoda- 
tion-time is greatest for points near the eye and decreases with 
the distance of the points from the eye. 
The investigations on reaction-time in relation to intensity 
and pitch, made by Dr. M. D. Slattery, lead to these con- 
clusions : 
1. The law that the reaction-time decreases with increas- 
ing intensity of stimulus does not hold good for the sense of 
hearing, i.e., the reaction-time to tones is nearly the same 
for all moderate intensities. 
2. The longer time registered for very weak tones or 
noises by some observers is probably not due to any con- 
scious change, but is caused by hesitation as to the actual 
hearing of the stimulus. 
3. The reaction-time to tones decreases as the pitch rises. 
4. The view held by Exner, von Kries, and Auerbach and 
rejected by Martins-namely, that about ten vibrations are 
necessary to the perception of a tone, no matter what its pitch 
-is sufficient to explain the differences in the reaction-times 
for different tones. 
5. In the domain of tactile stimulation by electricity the 
reaction-time decreases with the increase in the intensity of 
the stimulus. 
The experiments of J. A. Gilbert on the musical sensitive- 
ness of school-children involved in the first place the invention 
of a new piece of apparatus, the tone-tester, which has proved 
an exceedingly convenient instrument for much demonstra- 
tional work on the psychological methods. The sensitiveness 
to differences in pitch increases with age ; at first rapidly, then SHOR TER CON TRIB UTIONS. 
69 
very slowly. The least perceptible difference at 6 years is 
of a tone, at 19 years it is At 10 years and at 15 years 
the sensitiveness suddenly falls off. 
A new reaction-key, designed to avoid the objections to the 
usual telegraph-key, is described in an article on the time of 
voluntary movement. Being a new instrument it opened up 
new methods of solution ; one of these was the measurement 
of the time of voluntary movement. The time of flexion of 
the finger was found to decrease as the distance of movement 
increased from 5 mm to 20 mm; the time of extension, how- 
ever, increased. This is explained by J. M. Moore as the 
result of the favorable leverage for the flexor muscles at 
the smaller distances. 
An article on drawing a straight line makes the attempt 
to apply experimental methods to pedagogical problems. 
The average errors for various positions, inclinations, grasps 
of the pencil, etc., were determined. 
The equipment of the workshop in the laboratory has 
proved an excellent investment. The room is the one most 
used in the building and is often quite overcrowded. To have 
accomplished without a workshop the amount of work actually 
done in the laboratory would have cost more than the two 
hundred dollars spent in its equipment; thus at the beginning 
of the second year we are in possession of a well-equipped 
workshop which has already paid for itself. The employment 
of a mechanic has furnished the opportunity for the invention 
of several pieces of apparatus. The multiple key has been 
much improved in a later model. A novel clock contact 
makes platinum contact in the middle of the arc of swing. 
A new drum built with the durability of a piece of machinery 
is run either by hand or by motor.