title: Reward modulates the mirror neuron system in schizophrenia: A study into the mu rhythm suppression, empathy, and mental state attribution.
abstract: Impairments in the mirror neuron system (MNS) have been implicated as a possible underlying neurological basis for deficits in higher-level social cognition in schizophrenia. Previous work testing this hypothesis has used the electroencephalographic mu rhythm as an index of MNS activity, with studies showing mixed results. Here we investigated the role that reward plays in modulating the mu rhythm, and its association with empathy and emotional mental state reasoning. A group of schizophrenia patients and a healthy control group completed an action observation paradigm in which they watched actions that were financially rewarding, punishing, or neutral. Patients showed intact reward-related modulation of the mu rhythm, and greater mu suppression was associated with greater negative symptoms. There was also a trend for reduced mu suppression in patients. Furthermore, both empathy and emotional mental state reasoning were associated with the degree of mu suppression, but only in healthy controls. These findings confirm the association between the mu suppression and high-level social cognition. It is possible that schizophrenia patients utilize different cognitive routes to infer mental states. The demonstration that reward influences the degree of mu suppression in schizophrenia patients may help to account for previous conflicting findings in the literature.
authors.affiliation: a Maryland Psychiatric Research Centre , University of Maryland School of Medicine , Baltimore , MD , USA.|b Division of Cognitive Neuropsychiatry and Psychiatric Preventive Medicine , LWL University Hospital, Ruhr University Bochum , Bochum , Germany.
authors.forename: Elliot C
authors.initials: EC
authors.lastname: Brown
authors.affiliation: b Division of Cognitive Neuropsychiatry and Psychiatric Preventive Medicine , LWL University Hospital, Ruhr University Bochum , Bochum , Germany.|c International Graduate School of Neuroscience (IGSN) , Ruhr University Bochum , Bochum , Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonzalez-Liencres
authors.affiliation: c International Graduate School of Neuroscience (IGSN) , Ruhr University Bochum , Bochum , Germany.|d Department of Psychology , Üsküdar University , Istanbul , Turkey.
authors.forename: Cumhur
authors.initials: C
authors.lastname: Tas
authors.affiliation: b Division of Cognitive Neuropsychiatry and Psychiatric Preventive Medicine , LWL University Hospital, Ruhr University Bochum , Bochum , Germany.|c International Graduate School of Neuroscience (IGSN) , Ruhr University Bochum , Bochum , Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Brüne
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D004645:Empathy; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D059167:Mirror Neurons / Q000502:physiology*; D011569:Psychiatric Status Rating Scales; D012201:Reward; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D066191:Sensorimotor Cortex / Q000503:physiopathology; D012938:Social Perception
keywords: Action observation; EEG; Perspective-taking; Schizophrenia; Social cognition