title: Mild Reinforcement Learning Deficits in Patients With First-Episode Psychosis.
abstract: Numerous studies have identified reinforcement learning (RL) deficits in schizophrenia. Most have focused on chronic patients with longstanding antipsychotic treatment, however, and studies of RL in early-illness patients have produced mixed results, particularly regarding gradual/procedural learning. No study has directly contrasted both rapid and gradual RL in first-episode psychosis (FEP) samples. We examined probabilistic RL in 34 FEP patients and 36 controls, using Go/NoGo (GNG) and Gain vs Loss-Avoidance (GLA) paradigms. Our results were mixed, with FEP patients exhibiting greater impairment in the ability to use positive, as opposed to negative, feedback to drive rapid RL on the GLA, but not the GNG. By contrast, patients and controls showed similar improvement across the acquisition. Finally, we found no significant between-group differences in the postacquisition expression of value-based preference in both tasks. Negative symptoms were modestly associated with RL measures, while the overall bias to engage in Go-responding correlated significantly with psychosis severity in FEP patients, consistent with striatal hyperdopaminergia. Taken together, FEP patients demonstrated more circumscribed RL impairments than previous studies have documented in chronic samples, possibly reflecting differential symptom profiles between first-episode and chronic samples. Our finding of relatively preserved gradual/procedural RL, in briefly medicated FEP patients, might suggest spared or restored basal ganglia function. Our findings of preserved abilities to use representations of expected value to guide decision making, and our mixed results regarding rapid RL, may reflect a lesser degree of prefrontal cortical functional impairment in FEP than in chronic samples. Further longitudinal research, in larger samples, is required.
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong.|State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong.
authors.forename: Wing Chung
authors.initials: WC
authors.lastname: Chang
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: James A
authors.initials: JA
authors.lastname: Waltz
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD.
authors.forename: James M
authors.initials: JM
authors.lastname: Gold
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong.
authors.forename: Tracey Chi Wan
authors.initials: TCW
authors.lastname: Chan
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong.|State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong.
authors.forename: Eric Yu Hai
authors.initials: EYH
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology; D030141:Feedback, Psychological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D011337:Probability Learning; D011597:Psychomotor Performance / Q000502:physiology*; D011618:Psychotic Disorders / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D012054:Reinforcement, Psychology; D012559:Schizophrenia / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: basal ganglia; decision making; dopamine; prediction error; prefrontal cortex; psychosis