title: Aberrant sense of agency in patients with schizophrenia: forward and backward over-attribution of temporal causality during intentional action.
abstract: Self-disturbances in schizophrenia have been explained and studied from the standpoint of an abnormal sense of agency. We devised an agency-attribution task that evaluated explicit experiences of the temporal causal relations between an intentional action and an external event, without any confounding from sense of ownership of body movement. In each trial, a square piece appeared on the bottom of a computer screen and moved upward. Subjects were instructed to press a key when they heard a beep. When the key was pressed, the piece jumped with various temporal biases. Subjects were instructed to make an agency judgment for each trial. We demonstrated that an excessive sense of agency was observed in patients with schizophrenia compared with normal controls. Moreover, patient groups had a greater tendency to feel a sense of agency even when external events were programmed to precede their action. Therefore, patients felt both forward and backward exaggerated causal efficacy in the temporal event sequence during the intentional action. Confusion in the experience of temporal causal relations between the self and the external world may underlie self-disturbances in schizophrenia.
authors.affiliation: Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. takaki@xa3.so-net.ne.jp
authors.forename: Takaki
authors.initials: T
authors.lastname: Maeda
authors.forename: Motoichiro
authors.initials: M
authors.lastname: Kato
authors.forename: Taro
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Satoru
authors.initials: S
authors.lastname: Iwashita
authors.forename: Masaru
authors.initials: M
authors.lastname: Mimura
authors.forename: Haruo
authors.initials: H
authors.lastname: Kashima
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D015984:Causality; D005260:Female; D006801:Humans; D033182:Intention; D007600:Judgment / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009068:Movement; D010775:Photic Stimulation; D011597:Psychomotor Performance; D011930:Reaction Time; D012559:Schizophrenia / Q000188:drug therapy; D012565:Schizophrenic Psychology; D018709:Statistics, Nonparametric; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents