1. P
Elizabeth I. Kim, David G. Weissman, Paul D. Hastings & Amanda E. Guyer
Center for Mind and Brain, Dept. Psychology, Dept. of Human Development,
University of California, Davis
INTRODUCTION RESULTS
Neurobiological Mechanisms Associated with
Facial Emotion Reactivity in Adolescents
CONCLUSIONS
ACKNOWLEDGMENTS
How
sad
does
this
person
make
you
feel? How
wide
is
the
nose?
Adolescents
responded
to
the
above
questions
from
1=
not
at
all
to
5=
extremely
Heart
Rate
Variability
•Measured
using
an electrocardiogram
•Edited
and
analyzed using MindWare
Technologies
HRV
Analysis
Software
•Respiratory sinus
arrhythmia
(RSA) values
were
used
to
measure
parasympathetic
nervous
system activity;
low
values
correlate
to
more
emotional
arousal
Participants
138
Mexican-­‐origin
adolescents
(75
male,
63
female)
participated
in
the
Faces
Task in
a
scanner
(MRI)
where they
were
shown faces
in
different
emotional
states
(neutral,
happy,
sad,
angry,
fearful)
and
asked
two
questions:
Amygdala
Activation
5.8
6
6.2
6.4
6.6
6.8
7
7.2
7.4
Baseline HowSad HowWide
RespiratorySinusArrhythmia
Baseline v. Task RSA
by Sex
Males Females
*
6.30
6.40
6.50
6.60
6.70
6.80
6.90
7.00
7.10
Baseline HowSad HowWide
RespiratorySinusArrhythmia
Baseline v. Task RSA
*
*
0
50
100
150
200
250
Baseline HowSad HowWide
SkinConductanceLevels
Baseline v. Task SCL
by Sex
Males Females
0
20
40
60
80
100
120
140
160
180
200
Baseline HowSad HowWide
SkinConductanceLevels
Baseline v. Task SCL
*
*
*
* *
-0.12
-0.10
-0.08
-0.06
-0.04
-0.02
0.00
HowSad HowWide
Beta-Values
Right Amygdala Activation
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
0.20
HowSad HowWide
BetaValues
Left Amygdala Activation
*
*
• Through
a
series
of
negative
feedback
regulatory
loops
in
the
central
autonomic
nervous
system,
humans
are
able
to
adapt
to
their
social
environments
(Thayer
and
Lane,
2000;
Fujimura
2012).
• This
study
explores
the
neurophysiological
mechanisms
associated
with
one
crucial
social
adaptive
skill
that
may
differ
between
the
sexes:
facial
emotion
processing.
• We
analyzed
three
neurobiological
mechanisms
indicative
of
emotional
reactivity,
which
have
been
shown
to
differ
in
their
function
in
some
contexts
between
male
and
female
adolescents.
• We
also
investigate
how
adolescent
emotional
reactivity
varies
as
a
function
of
the
way
in
which
emotional
faces
are
processed.
For
this
reason,
participants
engage
in
both
implicit
emotion
processing
and
emotional
self-­‐reflection.
• Emotional
self-­‐reflection
is
simply
the
process
in
which
the
participant expresses
how
he/she
feels
about
the
faces.
Emotional
Faces
fMRI
Task
Higher
resting
HRV
has
been
correlated
with
greater
behavioral
flexibility
and
more efficient
emotion
regulation
(Thayer
and
Lane,
2000;
Fujimura,
2012)
while
lower
resting
HRV
has
been
correlated
with
poor
habituation
to
emotional
valences
(Friedman &
Thayer,
1998).
Our
results
suggest
that
females
may
have
a
greater
ability
to
adapt
to
different
emotional
valences
(Thayer
and
Lane,
2000)
since
females
had
generally
higher
HRV
than
males,
though
only
significantly
higher
RSA
during
implicit
emotion
processing
in
this
project. In
turn,
males
had
significantly
higher
SCL
than
females
overall
which
could
be
attributed
to
overly
sensitive
mechanisms
(vagal
tone and
SCL)
underlying
emotion
reactivity
(Fujimara,
2012).
For
these
reasons
and
with
the
results
from
our
data,
we
may
conclude
that
the
difference
in
activation
of
PNS
and
SNS
during
facial
emotion
reactivity,
measured
by
RSA
and
SCL
in
our
study,
is
due
to
the
possibility
that
females
have
greater
adaptability
to
their
social
environments
while
males
experience
a
“blunting
of
subjective
emotional
reactions”
(Sollers et
al.,
1997).
Though
no
significant
difference
was
found
in
amygdala
activation
between
the
sexes,
we
see
an
interesting
activation
of
the
left
amygdala
during
the
task.
Left
amygdala
responds
in
different
ways
depending
on
task
demands,
with
greater
activation
during
the
implicit
processing
portion
of
the
task
and
significantly
less
during
emotional
self-­‐reflection.
Further research
should
be
done
to
more
thoroughly
examine
the
context
in
which
the
left
amygdala
is
activated
during
emotion
processing.
To
better
understand
the
results
of
this
study
as
a
whole,
further
research
on
the
topic
should
include
individual,
within-­‐subject
analysis
(rather
than
the
use
of
average
values)
and
an
emotion
processing
task
that
measures
emotion
reactivity
as
well
as
emotion
regulation
in
participants.
Galvanic
Skin
Response
•Measured
using
two
electrodes
on
the
hand
•Analyzed
with
MindWare Technologies
Electrodermal Activity
(EDA)
Analysis
Software
•Skin
conductance
levels
(SCL)
used
to
measure
sympathetic
nervous
system
activity;
high
values
indicate
higher
emotional
arousal
This
work
was
supported
by
NIH
grant
R01
MH098370 (PI:
Amanda
Guyer,
Paul
Hastings)
David Weissman,
Nicole
Welindt,
and
Tim
Bell
also
contributed
a
great
deal
to
this
project.
Mindware
HRV
Analysis
Software
METHOD
Sharp
red
spikes=
R-­‐spike
Blue
dots
=
R-­‐spike
placements