The Eaton Democrat. (Eaton, Ohio) 1875-1903, 1878-06-06
How Fast Can You Think!
lscientifc American.

- Ike oNiCutlAiC go
"Quick as thought" and "quick as
lightning" are commonly used as synony-
nous expressions. But their difference
is really great. An electic impulse
trayerses a wire as a wave Of motion; a.
nervous impulse proceeds by a develop
ment of chemical change in the nerve.
1t runs along the nerve somewhat as
combustion follows a train of gunpow-
der, and not much if any more rapidly.
Indeed Helmholtz has clearly deter
mined the rate of nervous propagation to
be less than a hundred feet a second,
or about a mile a minute. To use q
rude illustration, if a railway could feel,
the ems report of a train starting in
New York would reach Albany but a
little in advance of the fastest trains
that have been run upon the Hudson
River road. Even along courses as
short as the nerves of the human body
an appreciable time is required for the
passage of nervous impulses.
With a simple apparatus. Hirsch
found that a touch upon the face could
be recognized and responded to by a
predetermined signal operated by the
hand, in one seventh of a second. With
a sound test, acting, of course, upon the
ear, the answering signal was made in
one-sixth of a second; when the eye
was addressed, the response came in
one-ifth of a second. Since the distance
travelled by the W impulses were
nearly the same in all these experiments,
it is evident that the greater part of
these differences of time noted must be
charged to the greater or smaller rapid
ity of the act of recognition; the entire
process in each case being the transmits
sion of a sensation (touch, hearing, or
sight to the brain, its recognition, the
willing of the signal agreed upon, the
transmission of the order to the mus
cles of the hand, and the movement of
those muscles. Thus it would appear
that less time is required for recogniz-
ing a touch than a sound, less time
to hear than to see. But what part of
the fifth, sixth OF seventh of a second,
as the case might be, was consumed in
the act of recognition?
Donders was successful in answering
this question by the use of several
forms of apparatus, involving entirely
different methods yet yielding the same
results. He found, for instance, with
the "noematachograph" that the
double act of recognizing a sound and
willing the response required seventy.
five thousandths of second. OF this
time, forty thousandths of second were
required for simple recognition, thus
leaving thirty.fve thousandths for wolf
ton. With the =" noematachometer y
he found that the same time, forty
thousandths Tor n twenty-ffth) of 8
second, was required to judge which
was first of two irritants acting on the
same sense. A slightly longer time wa.
required to judge the priority of signal,
acting on different senses, a sound and {
light. 1t also took longer to recognize
a letter by seeing its form than by hear
ing its sound.
This in a man of middle age. Youn,
people thought quicker, but the differ
ence was not great. In all the expert
ments the time required for a simpl,
thought was never less than a forfeit
of a second. In other words the mint
can perform not more than twenty-fou.
hundred simple acts a minute, ffteel
hundred a minute being the rate fo
persons of middle age.
From these figures it will be seen how
absurd are many popular notions in re
gard to the feetness of thought, hoy
exaggerated are the terrors of remorsefu
memory that moralists have ~invente,
for the method of dying. And we ma,
reasonably Discount alse the storie
told by men saved from drowning, Gu
down before death by hanging, or res
cued from sudden and deadly peril fror
other causes. No doubt a man ma,
think of a great multitude of experience
good or bad, in a few minutes; but tia
the thoughts and emotions of a long lif
may surge through the mind during tn
seconds of asphyxiation are manifesto
impossible.
Admit that the speed ofmental actio
is abnormally rapid at such times; sa
twenty-five hundred simple cognitions
minute, or one hundred and fifty thol
sand an hour. If a man were an hou
in drowning, instead of a few minute
and all the time be given to a mental n
view of life, he would, if forty yea
old, have time to give ten thoughts
the simplest character to each day ths
he lived. In other words memory woul
have time to review the experiences {
at most the hundredth part of OF
second out of each days waking tho
sands.