title: Amygdala hyperactivation to angry faces in intermittent explosive disorder.
abstract: Individuals with intermittent explosive disorder (IED) were previously found to exhibit amygdala hyperactivation and relatively reduced orbital medial prefrontal cortex (OMPFC) activation to angry faces while performing an implicit emotion information processing task during functional magnetic resonance imaging (fMRI). This study examines the neural substrates associated with explicit encoding of facial emotions among individuals with IED.
  
  
  
  Twenty unmedicated IED subjects and twenty healthy, matched comparison subjects (HC) underwent fMRI while viewing blocks of angry, happy, and neutral faces and identifying the emotional valence of each face (positive, negative or neutral). We compared amygdala and OMPFC reactivity to faces between IED and HC subjects. We also examined the relationship between amygdala/OMPFC activation and aggression severity.
  
  
  
  Compared to controls, the IED group exhibited greater amygdala response to angry (vs. neutral) facial expressions. In contrast, IED and control groups did not differ in OMPFC activation to angry faces. Across subjects amygdala activation to angry faces was correlated with number of prior aggressive acts.
  
  
  
  These findings extend previous evidence of amygdala dysfunction in response to the identification of an ecologically-valid social threat signal (processing angry faces) among individuals with IED, further substantiating a link between amygdala hyperactivity to social signals of direct threat and aggression.
authors.affiliation: Department of Psychology, Temple University, Philadelphia, PA, USA. Electronic address: mikemccloskey@temple.edu.
authors.forename: Michael S
authors.initials: MS
authors.lastname: McCloskey
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA; Mental Health Service Line, Jesse Brown VA Medical Center, Chicago, IL, USA.
authors.forename: K Luan
authors.initials: KL
authors.lastname: Phan
authors.affiliation: Department of Psychiatry, The University of Michigan, Ann Arbor, MI, USA.
authors.forename: Mike
authors.initials: M
authors.lastname: Angstadt
authors.affiliation: Department of Psychology, Temple University, Philadelphia, PA, USA.
authors.forename: Karla C
authors.initials: KC
authors.lastname: Fettich
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, Chicago, IL, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Keedy
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, Chicago, IL, USA.
authors.forename: Emil F
authors.initials: EF
authors.lastname: Coccaro
mesh_terms: D000328:Adult; D000679:Amygdala / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000786:Anger; D001931:Brain Mapping; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D006240:Happiness; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology
keywords: Aggression; Amygdala; Explicit emotion information processing; Faces; Intermittent explosive disorder; fMRI