title: Mirror neuron function, psychosis, and empathy in schizophrenia.
abstract: Processing of social and emotional information has been shown to be disturbed in schizophrenia. The biological underpinnings of these abnormalities may be explained by an abnormally functioning mirror neuron system. Yet the relationship between mirror neuron system activity in schizophrenia, as measured using an electroencephalography (EEG) paradigm, and socio-emotional functioning has not been assessed. The present research measured empathy and mirror neuron activity using an established EEG paradigm assessing the integrity of the Mu rhythm (8-13Hz) suppression over the sensorimotor cortex during observed and actual hand movement in 16 schizophrenia-spectrum disorder (SSD) participants (n=8 actively psychotic and n=8 in residual illness phase) and 16 age- and gender-matched healthy comparison participants. Actively psychotic SSD participants showed significantly greater mu suppression over the sensorimotor cortex of the left hemisphere than residual phase SSD and healthy comparison individuals. The latter two groups showed similar levels of mu suppression. Greater left-sided mu suppression was positively correlated with psychotic symptoms (i.e., greater mu suppression/mirror neuron activity was highest among subjects with the greater severity of psychotic symptoms). SSD subjects tended to have significantly higher levels of Personal Distress (as measured by the Interpersonal Reactivity Index) than healthy participants. The present study suggests that abnormal mirror neuron activity may exist among patients with schizophrenia during the active (psychotic) phase of the illness, and correlates with severity of psychosis.
authors.affiliation: Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA, USA. laurie-mccormick@uiowa.edu
authors.forename: Laurie M
authors.initials: LM
authors.lastname: McCormick
authors.forename: Michael C
authors.initials: MC
authors.lastname: Brumm
authors.forename: Janelle N
authors.initials: JN
authors.lastname: Beadle
authors.forename: Sergio
authors.initials: S
authors.lastname: Paradiso
authors.forename: Thoru
authors.initials: T
authors.lastname: Yamada
authors.forename: Nancy
authors.initials: N
authors.lastname: Andreasen
mesh_terms: D058256:Brain Waves / Q000502:physiology; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D004569:Electroencephalography; D004645:Empathy / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D059167:Mirror Neurons / Q000502:physiology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000209:etiology*; D012559:Schizophrenia / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D012565:Schizophrenic Psychology; D011795:Surveys and Questionnaires