Preferential amygdala reactivity to the negative assessment of neutral faces.
BACKGROUND
Prior studies suggest that the amygdala shapes complex behavioral responses to socially ambiguous cues. We explored human amygdala function during explicit behavioral decision making about discrete emotional facial expressions that can represent socially unambiguous and ambiguous cues.


METHODS
During functional magnetic resonance imaging, 43 healthy adults were required to make complex social decisions (i.e., approach or avoid) about either relatively unambiguous (i.e., angry, fearful, happy) or ambiguous (i.e., neutral) facial expressions. Amygdala activation during this task was compared with that elicited by simple, perceptual decisions (sex discrimination) about the identical facial stimuli.


RESULTS
Angry and fearful expressions were more frequently judged as avoidable and happy expressions most often as approachable. Neutral expressions were equally judged as avoidable and approachable. Reaction times to neutral expressions were longer than those to angry, fearful, and happy expressions during social judgment only. Imaging data on stimuli judged to be avoided revealed a significant task by emotion interaction in the amygdala. Here, only neutral facial expressions elicited greater activity during social judgment than during sex discrimination. Furthermore, during social judgment only, neutral faces judged to be avoided were associated with greater amygdala activity relative to neutral faces that were judged as approachable. Moreover, functional coupling between the amygdala and both dorsolateral prefrontal (social judgment > sex discrimination) and cingulate (sex discrimination > social judgment) cortices was differentially modulated by task during processing of neutral faces.


CONCLUSIONS
Our results suggest that increased amygdala reactivity and differential functional coupling with prefrontal circuitries may shape complex decisions and behavioral responses to socially ambiguous cues.
Blasi
Giuseppe
G
Psychiatric Neuroscience Group, Department of Neurological and Psychiatric Sciences, University of Bari, Bari, Italy.
Hariri
Ahmad R
AR
Alce
Guilna
G
Taurisano
Paolo
P
Sambataro
Fabio
F
Das
Saumitra
S
Bertolino
Alessandro
A
Weinberger
Daniel R
DR
Mattay
Venkata S
VS
D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001931:Brain Mapping; D003657:Decision Making / Q000502:physiology*; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D011287:Prejudice; D011930:Reaction Time; D012938:Social Perception