title: Dissociable patterns of medial prefrontal and amygdala activity to face identity versus emotion in bipolar disorder.
abstract: BACKGROUND
  Individuals with bipolar disorder demonstrate abnormal social function. Neuroimaging studies in bipolar disorder have shown functional abnormalities in neural circuitry supporting face emotion processing, but have not examined face identity processing, a key component of social function. We aimed to elucidate functional abnormalities in neural circuitry supporting face emotion and face identity processing in bipolar disorder.
  
  
  METHODS
  Twenty-seven individuals with bipolar disorder I currently euthymic and 27 healthy controls participated in an implicit face processing, block-design paradigm. Participants labeled color flashes that were superimposed on dynamically changing background faces comprising morphs either from neutral to prototypical emotion (happy, sad, angry and fearful) or from one identity to another identity depicting a neutral face. Whole-brain and amygdala region-of-interest (ROI) activities were compared between groups.
  
  
  RESULTS
  There was no significant between-group difference looking across both emerging face emotion and identity. During processing of all emerging emotions, euthymic individuals with bipolar disorder showed significantly greater amygdala activity. During facial identity and also happy face processing, euthymic individuals with bipolar disorder showed significantly greater amygdala and medial prefrontal cortical activity compared with controls.
  
  
  CONCLUSIONS
  This is the first study to examine neural circuitry supporting face identity and face emotion processing in bipolar disorder. Our findings of abnormally elevated activity in amygdala and medial prefrontal cortex (mPFC) during face identity and happy face emotion processing suggest functional abnormalities in key regions previously implicated in social processing. This may be of future importance toward examining the abnormal self-related processing, grandiosity and social dysfunction seen in bipolar disorder.
authors.affiliation: Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. keenermt@upmc.edu
authors.forename: M T
authors.initials: MT
authors.lastname: Keener
authors.forename: J C
authors.initials: JC
authors.lastname: Fournier
authors.forename: B C
authors.initials: BC
authors.lastname: Mullin
authors.forename: D
authors.initials: D
authors.lastname: Kronhaus
authors.forename: S B
authors.initials: SB
authors.lastname: Perlman
authors.forename: E
authors.initials: E
authors.lastname: LaBarbara
authors.forename: J C
authors.initials: JC
authors.lastname: Almeida
authors.forename: M L
authors.initials: ML
authors.lastname: Phillips
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001714:Bipolar Disorder / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D004644:Emotions; D005145:Face; D005149:Facial Expression; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010364:Pattern Recognition, Visual; D017397:Prefrontal Cortex / Q000503:physiopathology*