title: Dopamine improves exploration after expectancy violations and induces psychotic-like experiences in patients with Parkinson's disease.
abstract: Dopamine neurons are sensitive to novel and rewarding events, and dopamine signals can modulate learning in higher-level brain networks. Additionally, dopamine abnormalities appear to be central to the pathophysiology of schizophrenia spectrum disorders. In this study, we investigate the dopaminergic modulation of schizotypal traits and exploration after expectancy violations in Parkinson's disease (PD) patients on dopamine replacement therapy. Exploration after expectancy violations was measured with a latent inhibition and an anomaly categorisation task. Patients with PD had significantly elevated levels of schizotypy and reduced latent inhibition, relative to the controls. Anomaly categorisation was enhanced at trend level among the patients. Dopaminergic antiparkinsonian drugs showed dose-dependent effects: they induced psychotic-like experiences, and at the same time, they disrupted latent inhibition and made categorisation of anomaly more efficient. Most of these findings were replicated in an independent sample of patients with PD. An up-regulated dopamine system in medicated PD patients might tune higher-level brain networks to engage in learning when faced with unexpected information, and therefore hasten the updating of internal models.
authors.affiliation: Budapest University of Technology and Economics, Department of Cognitive Science, Egry József utca 1., T/5/506., 1111 Budapest, Hungary; Nyírő Gyula Hospital-National Institute of Psychiatry and Addiction, Lehel utca 59., 1135 Budapest, Hungary. Electronic address: polner.b@gmail.com.
authors.forename: Bertalan
authors.initials: B
authors.lastname: Polner
authors.affiliation: School of Social Sciences and Psychology & Marcs Institute for Brain and Behaviour, Western Sydney University, Locked Bag 1797, Penrith, 2751 Sydney, New South Wales, Australia.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Moustafa
authors.affiliation: National Institute of Medical Rehabilitation, Szanatórium utca 19., 1528 Budapest, Hungary; Semmelweis University, Department of Neurology, Balassa utca 6., 1083 Budapest, Hungary.
authors.forename: Helga
authors.initials: H
authors.lastname: Nagy
authors.affiliation: Semmelweis University, Department of Neurology, Balassa utca 6., 1083 Budapest, Hungary.
authors.forename: Annamária
authors.initials: A
authors.lastname: Takáts
authors.affiliation: Nyírő Gyula Hospital-National Institute of Psychiatry and Addiction, Lehel utca 59., 1135 Budapest, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Győrfi
authors.affiliation: Budapest University of Technology and Economics, Department of Cognitive Science, Egry József utca 1., T/5/506., 1111 Budapest, Hungary; Nyírő Gyula Hospital-National Institute of Psychiatry and Addiction, Lehel utca 59., 1135 Budapest, Hungary; University of Szeged, Institute of Physiology, Dóm tér 10., 6720 Szeged, Hungary.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Kéri
mesh_terms: D000978:Antiparkinson Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D015259:Dopamine Agents / Q000627:therapeutic use*; D018491:Dopamine Agonists / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D021641:Recognition, Psychology
chemical_list: D000978:Antiparkinson Agents; D015259:Dopamine Agents; D018491:Dopamine Agonists
keywords: Dopamine; Exploration; Latent inhibition; Parkinson’s disease; Psychosis