Birmingham state herald. (Birmingham, Ala.) 1895-1897, 1897-02-16
THE HOBART CLUB MEET
An Able Discussion of Psyche
logical Measurements
BY PROFESSOR F. M. ROOF
Which Proved Interesting as Well as instructive
Some Tests on Memory" Next
Subject to Be Discussed.


At the meeting of the Herbart club Sat
urday night Prof F. Nj. Roof presented
the results of some of his Investigations
in psychological measurements. He pre-
scented a number of interesting tables
and illustrated the method of making
measurements of mental phenomena by
piece of apparatus designed and made b.
himself and Prof. A. c. Moore.
The following is a synopsis Of Prof.
Roofs paper:
TIME RELATION OF MENTAL PHE-
81 NOMENA.
Psychometry is that branch of expert
mental psychology which seeks to de-
termine the time-relations of mental phe-
nomena.
The subject, though yet in its infancy,
is already attracting widespread atten-
ton in psychological circles 1t must be
admitted however, that the growing pop
ularity of this branch of study is due
not so much to it's present achievements
as to the hopes for its future. 1t Is yet
too new and too complex to boast of
many results. Time, patience and PAINS
taking experiment are elements which
alone can tell what fruits it shall bear.
In fact the entire subject of expert
mental psychology is a new field and un-
explored. It is not. however, new the
ory or system of psychology, as some
have enormously claimed.
It's business is to deal with facts, not
theories. A theory is but logical guess,
and can only serve, at least, as work
ing basis for investigation.
And as to systems of psychology, there
can be but one true system. But what
that system is, is not yet clearly MADE
out. Introspection and observation nave
discovered many important truths con-
corning mental activity, it is true. But
the persistent disagreement of the doc
tors must of necessity fill the mere stu
dent with doubt and mystificatien. Inc
continual wranglings and heated contro-
versies of high authorities on the sub
ject whatever else they may prove. DEM
onstrate to the thinking mind one fact;
and that is, that the science of psychol-
ogy so far as human knowledge is con-
cerned, is yet in an exceedingly crude
state and must so remain until erroneous
theories are winnowed out from estah-
lished truths.
The department of experimental
psychology arrogates to itself no patent
insight into these things. 1t is work of
patient and pains-taking investigation,
an earnest seeking for more light, with
a candid recognition of the great dark
ness which still surrounds US. 1t is
neither the champion nor the antagonist
of any old-time school, creed or theory;
but on the contrary, shuns as far as pos,
sble all theological and theoretical
prejudices and controversies and sets 1t
self to the task of studying mental
phenomena in their relations to nervous
activity. Psychology furnishes the end,
physiology the means of investigation.
Hence, the psychological laboratory,
though new, is not fad. This is evil
denced by the important place accorded
it in many of the institutions of philoso-
phical Germany, and in such American
institutions as Yale, Harvard and the
universities of New York and Chicago. Z
"As quick as thought is an old say
ing. but experiment demonstrates the
fact that thought is a complex process,
and may be measured.
All psychometrical experiments must of
necessity, begin with simple reaction
time. This time. when found. furnishes
a measure for the more complicated re-
actions of recognition, discrimination,
volition and association.
Simple reaction time is the interval OF
time which elapses between the instant of
receiving a peripheral stimulation in
sense-organ, and the instant of response
by means of some form OF resulting mo-
ton previously agreed upon. For exam
pie the observer (the person experiment
ed upon) feels an electric shock, hears
the crack of the electric spark. sees
fash of light color, figure, letter or
word and instantly signals that he per-
cefves the stimulation. An instrument
prepared for the purpose records tine
point of time when the stimulus was APP
piled and the point when the answering
signal was returned. The elapsing inter-
val is the reaction---time.
Various pieces of apparatus, ali OF
which are as yet more or less imperfect,
are employed for recording the time.
One of these contrivances is metallic
cylinder known as the electric drum.
When an experiment is to be performed
a sheet of paper is wrapped closely
around this drum (the joining ends be-
ing secured with mucilage) and is then
smoked black. A marker is so arranged
that one end touches this smoked sur
face while the other end is connected
with a tuning-fork which vibrates 100
times in a second. the vibrations being
kept up by an electric current. The
drum is then revolved rapidly by means
of electricity, the marker making a con-
tinuous white wave line upon the smaked
surface, 100 waves mark second OF
time. The arrangement for commun1-
eating the stimulus to the observer Is
such that 1t closes the current causing
an electric spark to escape through the
marker, puncturing the wave-line with
a white star. The response is recorded
in the same manner; and the waves be-
tween the stars give the re-action-time
in hundredths of second.
Other contrivances may be used in
place of the tuning fork, such as the
metronome, for instance, which marks
the line with regular reflections, caused
by the vibrating pendulum. But enough
has been said to illustrate the method.
Another device, and perhaps one of the
best for measuring all reaction-time de-
pendent upon the stimulus of vision, is
the pendulum chronoscope The pendu-
lum Of this apparatus vibrates with
known velocity along graduated arc.
Vibrating with the pendulum, but dis
connected from it by separate at
tachment at the top is pointer. The
lower end of this pointer vibrates on the
inside of the arc in a groove which may
be instantly closed with spring attach
ment, thereby stopping the pointer and
holding it fast.
The operator sits on the pendulum side
of the apparatus and the observer on the
opposite side, with an Opaque partition
between. In this partition is a small
aperture through which the observer
catches sight of the objects exposed for
that purpose by the operator. When the
machine is set" the aperture is closed
with trap-door, but the releasement of
the pendulum at zero drops the trap
door, exposing the inner view to the OBJ
server, who instantly presses the lever,
tt,araI,xy ra1aa cinp tha snrinQ and StODDing