An fMRI study of the neural correlates of incidental versus directed emotion processing in pediatric bipolar disorder.
OBJECTIVE
To use functional neuroimaging to probe the affective circuitry dysfunctions underlying disturbances in emotion processing and emotional reactivity in pediatric bipolar disorder (PBD).


METHODS
Equal numbers of controls (HC) and unmedicated patients with euthymia and PBD were matched for age, sex, race, socioeconomic status, and IQ (n = 10 per group; mean age 14.2 years [SD 2.0 years]). The task consisted of a "directed" emotion processing condition where subjects judged whether emotion in facial expression was positive or negative and an "incidental" condition where subjects judged whether faces expressing similar affect were older or younger than 35 years.


RESULTS
Relative to the directed condition, the incidental condition elicited greater activation in the right amygdala and the right insula, the left middle frontal gyrus, and the left posterior cingulate cortex in patients with PBD, in contrast to the HC that showed greater activation in the right superior frontal gyrus. In both incidental and directed conditions, relative to visual fixation, patients with PBD showed less activation in the right prefrontal cortex (superior, middle, and inferior frontal gyri) and the pregenual anterior cingulate cortex and greater activation in the posterior visual and face-processing regions (i.e., right precuneus/cuneus, fusiform gyrus).


CONCLUSIONS
Increased amygdala activation observed in patients with PBD elicited by incidental emotional processing relative to directed emotional processing may indicate more intense automatic emotional reactivity. Furthermore, the right prefrontal systems that are believed to modulate affect seem to be less engaged in patients with PBD regardless of whether the emotion processing is incidental or directed, which may signify reduced top-down control of emotional reactivity in PBD.
Pavuluri
Mani N
MN
All of the authors are with the Center for Cognitive Medicine, University of Illinois at Chicago. Drs. Pavuluri and Passarotti are also with the Institute for Juvenile Research. Electronic address: mpavuluri@psych.uic.edu.
Passarotti
Alessandra M
AM
All of the authors are with the Center for Cognitive Medicine, University of Illinois at Chicago. Drs. Pavuluri and Passarotti are also with the Institute for Juvenile Research.
Harral
Erin M
EM
All of the authors are with the Center for Cognitive Medicine, University of Illinois at Chicago. Drs. Pavuluri and Passarotti are also with the Institute for Juvenile Research.
Sweeney
John A
JA
All of the authors are with the Center for Cognitive Medicine, University of Illinois at Chicago. Drs. Pavuluri and Passarotti are also with the Institute for Juvenile Research.
D000293:Adolescent; D000679:Amygdala / Q000503:physiopathology; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology*; D001714:Bipolar Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology