1. Undergraduate
Category:
Interdisciplinary
Topics,
Centers
and
Ins7tutes
Degree
Level:
Bachelor’s
Abstract
ID#:
851
Electrodermal
Correlates
of
Reward
Sensi4vity
in
Emo4on
Percep4on
Under
Stress
J
SenF,
T
Stallings,
S
Lynn,
K
Quigley,
LF
BarreJ
Psychology,
Northeastern
University
Abstract
Judging
the
emo7onal
state
of
another
person,
such
as
whether
he
or
she
is
angry
or
not,
is
something
people
do
moment-­‐to-­‐moment
in
every
social
interac7on.
We
examined
the
rela7onship
between
people's
psychophysiological
response
to
a
social
stress
induc7on
(a
public
speaking
task)
and
their
ability
to
subsequently
make
effec7ve
judgments
about
facial
expressions
in
a
separate
anger
detec7on
task.
Par7cipants
earned
and
lost
points
for
correct
vs.
incorrect
iden7fica7on
of
anger
on
the
detec7on
task.
We
found
significant
correla7ons
between
electrodermal
ac7vity
(EDA)
during
the
stress
induc7on
and
how
people
weighted
the
benefits
and
costs
of
correct
vs.
incorrect
emo7on
judgments.
Par7cipants
who
showed
a
larger
increase
(over
res7ng
baseline)
in
EDA
underscores
responded
less
impulsively
to
rewards
in
the
anger
detec7on
task.
Increases
in
EDA
are
associated
with
psychological
arousal
and
orienta7on
to
events
in
the
environment.
Our
results
are
congruent
with
studies
of
stress
showing
that,
in
some
contexts,
stress
can
improve
decision-­‐making.
Our
results
suggest
that
one
mechanism
by
which
stress
may
improve
decision-­‐
making
is
by
increasing
the
accuracy
of
a
person's
assessment
of
the
benefits
and
costs
of
decision
outcomes.
Introduc4on
Throughout
this
study,
signal
detec7on
theory
was
used
to
model
how
people
adapt
their
risk
exposure
as
uncertainty
changes.
Through
measurement
of
psychophysiology
specifically,
electrodermal
ac7vity
(EDA),
which
demonstrates
the
autonomic
changes
in
the
electrical
proper7es
of
the
skin,
we
were
able
to
measure
their
response
bias
following
a
“Correct
Detec7on”
(CD)
or
“Correct
Rejec7on”(CR)
during
the
anger
detec7on
task.
EDA
response
is
generally
regarded
as
an
orienta7on
response
to
salient
events.
Results
Following
a
CD
or
a
CR,
par7cipants
with
lower
EDA
tended
to
perseverate
on
the
key
(Yes
or
No)
that
had
resulted
in
a
reward.
Their
behavior
following
a
CD
or
CR
was
influenced
by
the
behavior
that
resulted
in
a
reward
to
begin
with.
Those
with
higher
EDA
had
subsequent
responses
that
were
less
biased
toward
their
previous
behavior.
Their
choices
tended
to
illustrate
more
ra7onal/less
biased
behavior
toward
each
instance
of
anger
detec7on.
Conclusion
The
results
of
this
study
show
that
higher
EDA
measurements
correlate
with
greater
overall
performance
on
the
anger
recogni7on
task.
Par7cipants
who
stayed
on
the
“Yes”
buJon
following
a
CD
and
those
who
stayed
on
the
“No”
buJon
following
a
CR
tended
to
have
lower
EDA,
and
were
more
liberal
in
their
response
bias.
Those
who
tended
to
switch
buJons
also
tended
to
have
higher
EDA.
That
response
caused
their
outcome
specific
bias
to
move
closer
to
0,
which
is
a
more
op7mal
response.
This
is
shown
to
be
more
ra7onal
behavior,
since
it
effec7vely
is
trea7ng
each
facial
expression
as
an
independent
event.
This
may
suggest
that
people
with
higher
EDA
cope
more
efficiently
with
social
stressors.
References
Lynn,
S.K,
and
L.F.
Barre/.
2014.
“U6lizing”
signal
detec6on
theory.
Psychological
Science,
25(9):1663–1673.
Fowles,
D.
C.,
Chris7e,
M.
J.,
Edelberg,
R.,
Grings,
W.
W.,
Lykken,
D.
T.,
&
Venables,
P.
H.
(1981).
Publica7on
recommenda7ons
for
electrodermal
measurements.
Psychophysiology,
18(3),
232-­‐239.
Further
Research
Direc4ons
• How
stressed
are
par7cipants?
What
does
that
have
to
do
with
threat
vs.
challenge
percep7on?
• Why
was
there
no
significant
correla7on
between
False
Alarms
and
Missed
Detec7ons
following
a
Correct
Detec7on
or
Correct
Rejec7on?
Methods
Par7cipants
categorized
faces
of
varying
scowl
intensity
as
"angry"
or
"not
angry"
(Figure
1).
Payoffs
for
correct
and
incorrect
categoriza7on
of
a
face
were
implemented
as
points
earned
or
lost
following
each
judgment.
Par7cipants
aJempted
to
op7mize
their
categoriza7on
of
the
faces
by
earning
as
many
points
as
they
could
over
1000
trials.
That
false
alarms
were
more
costly
than
missed
detec7ons
imposed
risk,
and
means
that
a
slight
bias
to
categorize
to
faces
as
"not
angry"
will
maximize
overall
points.
We
created
"angry"
and
"not
angry"
categories
by
imposing
two
Gaussian
distribu7ons
over
a
range
of
scowling
facial
depic7ons.
Overlap
of
distribu7ons
causes
perceptual
uncertainty,
and
means
that
the
same
intensity
of
scowl
is
an
instance
of
"anger"
on
some
trials
but
not
on
others.
The
target:
foil
base
rate
specified
the
propor7on
of
"angry"
to
"not
angry"
trials
shown.
We
recruited
134
adults,
largely
college
students,
ranging
from
18-­‐55
years
old,
the
mean
age
being
23.7
±
8.25
(1SD)
years.
62%
of
the
par7cipants
were
female.
Par7cipants
visited
the
lab
twice,
experiencing
different
similari7es,
base
rates,
or
point
values
on
each
visit.
On
the
second
visit,
we
applied
electrodes
to
record
psychophysiology
including
heart
rate,
respiratory
rate,
electrodermal
ac7vity,
and
blood
pressure.
As
part
of
visit
2
data,
we
analyzed
par7cipant's
skin
conductance
response
levels
in
response
to
a
social
stress
induc7on
(the
Trier
Social
Stress
Task)
and
their
ability
to
make
a
“CD”
or
a
“CR"
in
rela7on
to
outcome
specific
mo7va7on.
Emo$on
percep$on
as
a
signal
detec$on
issue.
The
perceptual
similarity
of
"angry"
(target)
and
"not
angry"
(foil)
categories,
target:
foil
base
rate
of
occurrence,
and
payoffs
for
correct
and
incorrect
categoriza7on
mathema7cally
determine
an
op7mal
decision
criterion
loca7on.
Figure
1:
Figure
2:
Figure
3:
Sensi4vity
to
Correct
Detec4on
rewards
as
a
func4on
of
EDA
!
R²!=!0.051!
)0.3!
)0.2!
)0.1!
0.0!
0.1!
0.2!
0.3!
0.4!
0.5!
0.6!
0.7!
0! 5! 10! 15! 20! 25! 30! 35! 40! 45!
Bias%following%correct%rejection%rewards%
Mean%skin%conductance%(micro%Siemens)%
for%stress%induction%speech,%minute%1%%
Sensi4vity
to
Correct
Rejec4on
rewards
as
a
func4on
of
EDA
Figure
4:
R²
=
0.009
-­‐1.2
-­‐1.0
-­‐0.8
-­‐0.6
-­‐0.4
-­‐0.2
0.0
0.2
0.4
0.6
0
5
10
15
20
25
30
35
40
45
Bias
following
missed
detec7ons
Mean
skin
conductance
(micro
Siemens)
for
stress
induc7on
speech,
minute
1
R²
=
0.014
-­‐1.5
-­‐1.0
-­‐0.5
0.0
0.5
1.0
0
5
10
15
20
25
30
35
40
45
Bias
following
false
alarms
Mean
skin
conductance
(micro
Siemens)
for
stress
induc7on
speech,
minute
1
Figure
5:
Sensi4vity
to
Missed
Detec4on
punishments
as
a
func4on
of
EDA
Sensi4vity
to
False
Alarm
punishments
as
a
func4on
of
EDA