title: Behavioral evidence of delayed prediction signals during agency attribution in patients with schizophrenia.
abstract: Self-disturbance, a core feature of schizophrenia, recently has been explained from the standpoint of an abnormal sense of agency (SoA). Previous studies showed that aberrant SoA in schizophrenia arise from imprecise predictions about the sensory consequences of actions. However, the nature of the malfunctioning predictions remains unclear. We examined the temporally "delayed" nature of inadequate predictions. We studied 30 patients with schizophrenia and 30 healthy controls. Our original SoA task evaluates explicit experience of the temporal causal relationship between an intentional action and an effect on a computer screen under the presence of temporal biases. We introduced an adaptation with a "trial-by-trial" method that prolonged or shortened the temporal biases. We hypothesized that delayed prediction signals in schizophrenia could lead to a match in timing between predictions and actual outcomes, resulting in self-agency. The adjustment courses to changing temporal biases were evaluated. Patients with schizophrenia continued to feel self-agency even when the adjusted temporal bias was longer than 1000ms. This result indicated that patient's prediction would be delayed in each trial. Our study empirically showed behavioral evidence for "delayed" prediction signals in a SoA paradigm for the first time.
authors: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan. Electronic address: rohikiakireko@yahoo.co.jp.
authors: Akihiro
authors: A
authors: Koreki
authors: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors: Takaki
authors: T
authors: Maeda
authors: Faculty of Sociology, Kansai University, Osaka, Japan.
authors: Hirokata
authors: H
authors: Fukushima
authors: Department of Psychology, Keio University, Tokyo, Japan.
authors: Satoshi
authors: S
authors: Umeda
authors: Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan.
authors: Keisuke
authors: K
authors: Takahata
authors: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors: Tsukasa
authors: T
authors: Okimura
authors: Department of Neuropsychiatry, Ashikaga Red Cross Hospital, Tochigi, Japan.
authors: Michitaka
authors: M
authors: Funayama
authors: Department of Psychiatry, Sakuragaoka Memorial Hospital, Tokyo, Japan.
authors: Satoru
authors: S
authors: Iwashita
authors: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors: Masaru
authors: M
authors: Mimura
authors: Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
authors: Motoichiro
authors: M
authors: Kato
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012677:Sensation / Q000502:physiology; D012938:Social Perception; D013997:Time Factors
keywords: Corollary discharge; Forward model; Prediction; Schizophrenia; Self; Self-disturbance; Sense of agency