Dopamine improves exploration after expectancy violations and induces psychotic-like experiences in patients with Parkinson's disease.
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.
['Polner|Bertalan|B|', 'Moustafa|Ahmed A|AA|', 'Nagy|Helga|H|', 'Takáts|Annamária|A|', 'Győrfi|Orsolya|O|', 'Kéri|Szabolcs|S|']
D000978:Antiparkinson Agents D016022:Case-Control Studies D015259:Dopamine Agents D018491:Dopamine Agonists D004305:Dose-Response Relationship, Drug D005260:Female D006801:Humans D007266:Inhibition, Psychological D008297:Male D008875:Middle Aged D010300:Parkinson Disease D010364:Pattern Recognition, Visual D010775:Photic Stimulation D021641:Recognition, Psychology
Dopamine Exploration Latent inhibition Parkinson’s disease Psychosis