Reaction time in the cold

Abstract

"Visual RT's were elicited from 620 soldiers sorted into 14 different groups representing a variety of ambient temperatures, windspeeds and windchills… . 1. At low windspeed… low ambient temperature has no effect on RS… . [reciprocal of RT]. 2. At windspeeds of 10 mph and greater, low ambient temperature produces a significant decrease in RA. 3. Windspeed produces a significant decrease in RS. 4. Mild exercise produces a small recover in RS. 5. If men of low 'physiological cold tolerance' are removed from the more severe environmental conditions and if Ss wear protective clothing, RS is essentially a linear decreasing function of windchill." (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Full text

Journal
oj
Applied
Psychology
Vol.
42, No. 1,
19S8
Reaction Time
in the
Cold
Warren
H.
Teichner
1
Quartermaster
Research
and
Development Center
As
reported
by
Forlano
(3) and by
Teich-
ner (7)
studies
of the
effects
of
cold envi-
ronments
on the
simple reaction time (RT)
suggest
that
RT is not
affected
by low
ambi-
ent
temperatures
down
to —
50°
F.
How-
ever, temperature
is
only
one of the
factors
which make
up
cold environments.
The
cool-
ing
power
of air
actually depends
on
both
its
temperature
and
speed
of
movement (wind-
speed).
The
effect
of
each
of
these, singly
and in
combination, must
be
studied
before
safe
generalizations
can be
made about
the
effect
of the
cold
on RT.
Further,
the
com-
bined action
of
temperature
and
wind (wind-
chill
2)
in
determining
the
cooling rate
of
exposed
bodies
has
been formulated
quantita-
tively; thus, there
is a
basis
for a
rational
ap-
proach
to the
combined
effects
problem.
It
was the
concern
of the
present investigation,
therefore,
to
study
the
effects
of the
cold
on
RT
through variation
of all
three physical
factors.
As
long
as 5s
wear protective clothing,
as
they have
in
previous studies,
S-R
relation-
ships
may be
misleading.
That
is,
with
no
information
beyond
the
stimulus conditions
and
S's
response,
it is not
possible
to
deter-
mine whether
the
environment
was
actually
effective
in
cooling
the
body. Failure
to find
a
temperature
effect
in
previous studies
may
have been
the
result
of
lack
of
actual body
cooling.
Thus,
studies which
fail
to
measure
1
Now at the
University
of
Massachusetts.
2
Windchill
is a
measure
of
that
part
of the
total
cooling
of a
body
due to the
action
of
wind.
The
term
is not
usually applied
to
temperatures above
freezing.
Values
of
windchill used
in
this
study
were
obtained
from
reference
(6)
based
on
Siple
and
Passel's
(5)
formula:
Ki>
=
(Viw
+
100
+
10.45
-
mi)
(33 -
T)
where:
KO
—
Total
cooling
in
kilogram calories
per
square
meter
per
hour,
IOT
=
Wind velocity
in
meters
per
second,
Ta
= Air
temperature
in
degrees centigrade.
body
cooling cannot yield information
of
gen-
eral
value
nor are the
results amenable
to
theoretical considerations, either physiologi-
cal
or
psychological.
The
present study
was
designed,
therefore,
to
obtain
body surface
temperatures
for
relationship
to the
effects
of
cold environments.
Method
Six
hundred
and
forty
infantrymen
from
Fort
Devens
were
used
as 5s.
20-man
groups were used,
one
per day
until
the
total
number
was
exhausted.
On
arrival
at the
laboratory
the 20 5s
were ran-
domly
sorted into
five-man
subgroups
and
each
op-
eration
of the
investigation
was
phased
to
handle
the
sequential appearance
of the
four
subgroups.
Two
subgroups were
studied
before
the
noon meal
and two
after
it.
Twenty
5s
were eliminated
for
medical reasons prior
to
starting.
5s
were taken
to a
dressing room
(55-60°
F.)
which
interconnected with
the
climatic chamber,
where
they undressed,
a
multi-point thermocouple
harness
was put on
them
and
they were dressed
in
appropriate clothing. These procedures were per-
formed
"by the
numbers"
so
that
all five Ss
were
dressed
at the
same time, thus avoiding individual
overheating. While
5s
were
in the
dressing room
standard instructions were read
to
them which
ex-
plained
the
details
of the
procedure
to
follow.
When
dressed, they
were
taken into
the
climatic chamber
which
was
pre-set
for the
appropriate environmental
conditions.
In the
chamber,
the five 5s sat
side
by
side about
three
ft.
apart,
before
a
long table
in
front
of a
large
observation window. They
faced
sideways
to
the
direction
of air
movement
and
were
in
front
view
of
technicians operating
the
equipment out-
side
of the
chamber. From their positions, however,
5s
were unable
to
observe
the
operation
of the
equipment.
5s sat
quietly
and
cooled
for the first 25
min.
During this time
the
instructions were read again
and
procedures demonstrated.
After
this they per-
formed
on a
manual dexterity task
for
about
20
min.
On
completion
of
this task
(45
min.
of
exposure),
5s
were seated
and 25
successive
RTs
were obtained.
This
procedure
was
completed
in
7-10 min.
Follow-
ing
this,
5s ran in
place slowly
for
three min. (mild
exercise),
performed
five
min. more
on the
psycho-
motor
task
and
then
10
more successive
RTs
were
obtained.
Each
5 was
provided with
a
Morse
key
fastened
to the
table.
At a
verbal ready signal,
Ss
closed
the
54