Negative symptoms and the failure to represent the expected reward value of actions: behavioral and computational modeling evidence (original) (raw)
Related papers
Reduced reward-related probability learning in schizophrenia patients
Neuropsychiatric disease and treatment, 2012
Although it is known that individuals with schizophrenia demonstrate marked impairment in reinforcement learning, the details of this impairment are not known. The aim of this study was to test the hypothesis that reward-related probability learning is altered in schizophrenia patients. Twenty-five clinically stable schizophrenia patients and 25 age- and gender-matched controls participated in the study. A simple gambling paradigm was used in which five different cues were associated with different reward probabilities (50%, 67%, and 100%). Participants were asked to make their best guess about the reward probability of each cue. Compared with controls, patients had significant impairment in learning contingencies on the basis of reward-related feedback. The correlation analyses revealed that the impairment of patients partially correlated with the severity of negative symptoms as measured on the Positive and Negative Syndrome Scale but that it was not related to antipsychotic dose....
Probabilistic reinforcement learning in schizophrenia: Relationships to anhedonia and avolition
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2016
BACKGROUND: Anhedonia (a reduced experience of pleasure) and avolition (a reduction in goal-directed activity) are common features of patients with schizophrenia that have substantial effects on functional outcome but are poorly understood and treated. We examined whether alterations in reinforcement learning may contribute to these symptoms in patients with schizophrenia by impairing the translation of reward information into goal-directed action. METHODS: Thirty-eight stable outpatients with schizophrenia or schizoaffective disorder and 37 healthy control subjects underwent functional magnetic resonance imaging scans during a probabilistic stimulus selection reinforcement learning task with dissociated choice-and feedback-related activation, followed by a behavioral transfer task allowing separate assessment of learning from positive versus negative outcomes. A Q-learning algorithm was used to examine functional activation relating to prediction error at the time of feedback and to expected value at the time of choice. RESULTS: Behavioral results suggested a reduction in learning from positive feedback in patients; however, this reduction was unrelated to anhedonia/avolition severity. On analysis of the functional magnetic resonance imaging scans, prediction error-related activation at the time of feedback was highly similar between patients and control subjects. During early learning, patients activated regions in the cognitive control network to a lesser extent than control subjects. Correlation analyses revealed reduced responses to positive feedback in dorsolateral prefrontal cortex and caudate among those patients higher in anhedonia/avolition. CONCLUSIONS: These results suggest that anhedonia/avolition are as strongly related to cortical learning or higherlevel processes involved in goal-directed behavior, such as effort computation and planning, as to striatally mediated learning mechanisms.
Neuropsychology of reward learning and negative symptoms in schizophrenia
Schizophrenia Research, 2014
We used the Iowa Gambling Test (IGT) to examine the relationship of reward learning to both neuropsychological functioning and symptom formation in 65 individuals with schizophrenia. Results indicated that compared to controls, participants with schizophrenia showed significantly reduced reward learning, which in turn correlated with reduced intelligence, memory and executive function, and negative symptoms. The current findings suggested that a disease-related disturbance in reward learning may underlie both cognitive and motivation deficits, as expressed by neuropsychological impairment and negative symptoms in schizophrenia.
Frontiers in human neuroscience, 2011
Contrasting theories of schizophrenia propose that the disorder is characterized by a deficit in phasic changes in dopamine activity in response to ongoing events or, alternatively, by a weakness in the representation of the value of responses. Schizophrenia patients have reliably reduced brain activity following incorrect responses but other research suggests that they may have intact feedback-related potentials, indicating that the impairment may be specifically response-related. We used event-related brain potentials and computational modeling to examine this issue by comparing the neural response to outcomes with the neural response to behaviors that predict outcomes in patients with schizophrenia and psychiatrically healthy comparison subjects. We recorded feedback-related activity in a passive gambling task and a time estimation task and error-related activity in a flanker task. Patients' brain activity following an erroneous response was reduced compared to comparison sub...
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2021
Background:The current study aimed to further etiological understanding of the psychological mechanisms underlying negative symptoms in people with schizophrenia. Specifically, we tested whether negative symptom severity is associated with reduced retention of reward-related information over time, and thus a degraded ability to utilize such information to guide future action selection.Methods:44 patients with a diagnosis of schizophrenia or schizoaffective disorder and 28 healthy volunteers performed a probabilistic reinforcement-learning task involving stimulus pairs in which choices resulted in reward or in loss avoidance. Following training, participants indicated their valuation of learned stimuli in a test/transfer phase. The test/transfer phase was administered immediately following training and one-week later. Percent retention was defined as accuracy at weeklong delay divided by accuracy at immediate delay.Results:Both healthy controls and people with schizophrenia showed similarly robust retention of reinforcement learning over a one-week delay interval. However, in the schizophrenia group, negative symptom severity was associated with reduced retention of information regarding the value of actions across a weeklong interval. This pattern was particularly notable for stimuli associated with reward compared to loss avoidance.Conclusions:Our results show that, although individuals with schizophrenia may initially learn about rewarding aspects of their environment, such learning decays at a more rapid rate in patients with severe negative symptoms. Thus, previously learned reward-related information may be more difficult to access to guide future decision-making and to motivate action selection.
Reward Processing in Schizophrenia: A Deficit in the Representation of Value
Schizophrenia Bulletin, 2008
Patients with schizophrenia demonstrate deficits in motivation and learning that suggest impairment in different aspects of the reward system. In this article, we present the results of 8 converging experiments that address subjective reward experience, the impact of rewards on decision making, and the role of rewards in guiding both rapid and long-term learning. All experiments compared the performance of stably treated outpatients with schizophrenia and demographically matched healthy volunteers. Results to date suggest (1) that patients have surprisingly normal experiences of positive emotion when presented with evocative stimuli, (2) that patients show reduced correlation, compared with controls, between their own subjective valuation of stimuli and action selection, (3) that decision making in patients appears to be compromised by deficits in the ability to fully represent the value of different choices and response options, and (4) that rapid learning on the basis of trial-to-trial feedback is severely impaired whereas more gradual learning may be surprisingly preserved in many paradigms. The overall pattern of findings suggests compromises in the orbital and dorsal prefrontal structures that play a critical role in the ability to represent the value of outcomes and plans. In contrast, patients often (but not always) approach normal performance levels on the slow learning achieved by the integration of reinforcement signals over many trials, thought to be mediated by the basal ganglia.
General functioning predicts reward and punishment learning in schizophrenia
Schizophrenia research, 2011
Previous studies investigating feedback-driven reinforcement learning in patients with schizophrenia have provided mixed results. In this study, we explored the clinical predictors of reward and punishment learning using a probabilistic classification learning task. Patients with schizophrenia (n = 40) performed similarly to healthy controls (n = 30) on the classification learning task. However, more severe negative and general symptoms were associated with lower reward-learning performance, whereas poorer general psychosocial functioning was correlated with both lower reward-and punishment-learning performances. Multiple linear regression analyses indicated that general psychosocial functioning was the only significant predictor of reinforcement learning performance when education, antipsychotic dose, and positive, negative and general symptoms were included in the analysis. These results suggest a close relationship between reinforcement learning and general psychosocial functioning in schizophrenia.
Mild Reinforcement Learning Deficits in Patients With First-Episode Psychosis
Schizophrenia bulletin, 2016
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,...