T U Hauser1, R Iannaccone2, R J Dolan1, J Ball2, J Hättenschwiler3, R Drechsler2, M Rufer4, D Brandeis2, S Walitza2, S Brem2. 1. Wellcome Trust Centre for Neuroimaging,University College London,London WC1N 3BG,UK. 2. Department of Child and Adolescent Psychiatry and Psychotherapy,Psychiatric Hospital, University of Zurich,8032 Zürich,Switzerland. 3. Anxiety Disorders and Depression Treatment Center Zurich (ADTCZ),Zurich,Switzerland. 4. Department of Psychiatry and Psychotherapy,University Hospital Zurich, University of Zurich,Zurich,Switzerland.
Abstract
BACKGROUND: Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks. METHOD: We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls. RESULTS: Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls. CONCLUSIONS: Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.
BACKGROUND:Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks. METHOD: We investigated neural mechanisms of decision making in OCDpatients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCDpatients with those of healthy matched controls. RESULTS:Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCDpatients also had a significantly lower perseveration parameter than controls. CONCLUSIONS: Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.
Entities:
Keywords:
Age of onset; anterior cingulate cortex; obsessive–compulsive disorder; reinforcement learning; reward prediction errors
Authors: Luke J Norman; Christina O Carlisi; Anastasia Christakou; Clodagh M Murphy; Kaylita Chantiluke; Vincent Giampietro; Andrew Simmons; Michael Brammer; David Mataix-Cols; Katya Rubia Journal: Biol Psychiatry Cogn Neurosci Neuroimaging Date: 2018-03-24