title: Disturbances of Agency and Ownership in Schizophrenia: An Auditory Verbal Event Related Potentials Study.
abstract: A 'sense of self' is essentially the ability to distinguish between self-generated and external stimuli. It consists of at least two very basic senses: a sense of agency and a sense of ownership. Disturbances seem to provide a basic deficit in many psychiatric diseases. The aim of our study was to manipulate those qualities separately in 28 patients with schizophrenia (14 auditory hallucinators and 14 non-hallucinators) and 28 healthy controls (HC) and to investigate the effects on the topographies and the power of the event-related potential (ERP). We performed a 76-channel EEG while the participants performed the task as in our previous paper. We computed ERPs and difference maps for the conditions and compared the amount of agency and ownership between the HC and the patients. Furthermore, we compared the global field power and the topographies of these effects. Our data showed effects of agency and ownership in the healthy controls and the hallucinator group and to a lesser degree in the non-hallucinator group. We found a reduction of the N100 during the presence of agency, and a bilateral temporal negativity related to the presence of ownership. For the agency effects, we found significant differences between HC and the patients. Contrary to the expectations, our findings were more pronounced in non-hallucinators, suggesting a more profoundly disturbed sense of agency compared to hallucinators. A contemporary increase of global field power in both patient groups indicates a compensatory recruitment of other mechanisms not normally associated with the processing of agency and ownership.
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.
authors.forename: Tim
authors.initials: T
authors.lastname: Bühler
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.|University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
authors.forename: Jochen
authors.initials: J
authors.lastname: Kindler
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.
authors.forename: Rahel C
authors.initials: RC
authors.lastname: Schneider
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Strik
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland. hubl@puk.unibe.ch.
authors.forename: Daniela
authors.initials: D
authors.lastname: Hubl
authors.affiliation: Translational Research Center, University Hospital of Psychiatry, University of Bern, 3000, Bern 60, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Koenig
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006212:Hallucinations / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D012649:Self Concept; D055815:Young Adult
keywords: Agency; Auditory evoked potential; Auditory verbal hallucination; N100; Ownership; Schizophrenia; Self-monitoring