title: Fronto-limbic and autonomic disjunctions to negative emotion distinguish schizophrenia subtypes.
abstract: Schizophrenia patients show a disconnection in amygdala-medial prefrontal cortex and autonomic arousal systems for processing fear. Concurrent functional magnetic resonance imaging [fMRI] and skin conductance recording were used to determine whether these disturbances are specific to fear, or present in response to other signals of danger. We also examined whether these disturbances distinguish a specific symptom profile. During scanning, 27 schizophrenia (13 paranoid, 14 nonparanoid) and 22 matched healthy control subjects viewed standardized facial expressions of fear, anger and disgust (versus neutral). Skin conductance responses [SCRs]were acquired simultaneously to assess phasic increases in arousal. 'With-arousal' versus 'without-arousal' responses were analysed using non-parametric methods. For controls, 'with-arousal' responses were associated with emotion-specific activity for fear (amygdala), disgust (insula) and anger (anterior cingulate), together with common medial prefrontal cortex [MPFC] engagement, as predicted. Schizophrenia patients displayed abnormally increased phasic arousal, with concomitant reductions in emotion-specific regions and MPFC. These findings may reflect a general disconnection between central and autonomic systems for processing signals of danger. This disjunction was most apparent in patients with a profile of paranoia, coupled with poor social function and insight. Heightened autonomic sensitivity to signals of fear, threat or contamination, without effective neural mechanisms for appraisal, may underlie paranoid delusions which concern threat and contamination, and associated social and interpersonal difficulties.
authors.affiliation: Brain Dynamics Centre, Westmead Hospital, NSW, 2145, Australia. lea@psych.usyd.edu.au
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Williams
authors.forename: Pritha
authors.initials: P
authors.lastname: Das
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Liddell
authors.forename: Gloria
authors.initials: G
authors.lastname: Olivieri
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Peduto
authors.forename: Anthony S
authors.initials: AS
authors.lastname: David
authors.forename: Evian
authors.initials: E
authors.lastname: Gordon
authors.forename: Anthony W F
authors.initials: AW
authors.lastname: Harris
mesh_terms: D000328:Adult; D000339:Affect; D000679:Amygdala / Q000503:physiopathology; D000786:Anger; D002540:Cerebral Cortex / Q000503:physiopathology; D005239:Fear; D005625:Frontal Lobe / Q000503:physiopathology*; D005712:Galvanic Skin Response; D006801:Humans; D008032:Limbic System / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D017397:Prefrontal Cortex / Q000503:physiopathology; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index