Amygdala response to facial expressions in children and adults.
BACKGROUND
The amygdala plays a central role in the human response to affective or emotionally charged stimuli, particularly fear-producing stimuli. We examined the specificity of the amygdala response to facial expressions in adults and children.


METHODS
Six adults and 12 children were scanned in a 1.5-T scanner during passive viewing of fearful and neutral faces using an EPI BOLD sequence. All scans were registered to a reference brain, and analyses of variance were conducted on the pooled data to examine interactions with age and gender.


RESULTS
Overall, we observed predominantly left amygdala and substantia innominata activity during the presentation of nonmasked fearful faces relative to fixation, and a decrease in activation in these regions with repeated exposure to the faces. Adults showed increased left amygdala activity for fearful faces relative to neutral faces. This pattern was not observed in the children who showed greater amygdala activity with neutral faces than with fearful faces. For the children, there was an interaction of gender and condition whereby boys but not girls showed less activity with repeated exposure to the fearful faces.


CONCLUSIONS
This is the first study to examine developmental differences in the amygdala response to facial expressions using functional magnetic resonance imaging.
Sackler Institute, Weill Medical College of Cornell University, New York, New York 10021, USA.
K M
KM
Thomas
W C
WC
Drevets
P J
PJ
Whalen
C H
CH
Eccard
R E
RE
Dahl
N D
ND
Ryan
B J
BJ
Casey
D000328:Adult; D000679:Amygdala / Q000033:anatomy & histology / Q000502:physiology*; D001143:Arousal / Q000502:physiology; D002648:Child; D005149:Facial Expression; D005260:Female; D005917:Globus Pallidus / Q000033:anatomy & histology; D006185:Habituation, Psychophysiologic / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012737:Sex Factors; D013377:Substantia Innominata / Q000033:anatomy & histology