Dataset Information

Increased conflict-induced slowing, but no differences in conflict-induced positive or negative prediction error learning in patients with schizophrenia.

ABSTRACT: People with schizophrenia (PSZ) often fail to pursue rewarding activities despite largely intact in-the-moment hedonic experiences. Deficits in effort-based decision making in PSZ may be related to enhanced effects of cost or reduced reward, i.e., through the amplification of negative prediction errors or by dampened positive prediction errors (here, positive and negative prediction errors refer to outcomes that are better or worse than expected respectively). We administered a modified Simon task to people with schizophrenia (PSZ; N?=?46) and healthy controls (N?=?32). The modification included a reinforcement learning component, where positive and negative prediction errors are dampened or boosted through the use of cognitively-effortful response conflict. EEG was recorded concurrently to investigate potential differences in conflict enhanced mid-frontal theta power between PSZ and controls. We found an enhanced effect of response conflict on response time in people with schizophrenia, but no discernible difference in conflict processing as reflected by the lack of a difference in theta-power enhancement to conflict in mid-frontal regions. Using the reinforcement learning transfer phase of the modified Simon task, PSZ also showed clear deficits in selecting the most rewarding stimulus during the 'easy' (most discriminable in terms of value) stimulus contrasts. However, we failed to find a difference between patients and controls in their gain or avoidance learning bias, nor did these biases correlate with negative symptoms. Previous studies had failed to find significant conflict effects on the Simon task likely due to its modest effect size. Our results show that PSZ do indeed possess subtle impairments in response-conflict, suggesting an increase in cognitive effort required for appropriate responding. In addition, while the lack of an overt positive or negative prediction error bias (i.e., a bias towards punishment or reward learning) was unexpected, it is consistent with recent work showing intact estimation of value when the reinforcement learning system is isolated from other contributors to value learning.

SUBMITTER: Albrecht MA

PROVIDER: S-EPMC7664161 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Increased conflict-induced slowing, but no differences in conflict-induced positive or negative prediction error learning in patients with schizophrenia.

Albrecht Matthew A MA Waltz James A JA Cavanagh James F JF Frank Michael J MJ Gold James M JM

Neuropsychologia 20180427

People with schizophrenia (PSZ) often fail to pursue rewarding activities despite largely intact in-the-moment hedonic experiences. Deficits in effort-based decision making in PSZ may be related to enhanced effects of cost or reduced reward, i.e., through the amplification of negative prediction errors or by dampened positive prediction errors (here, positive and negative prediction errors refer to outcomes that are better or worse than expected respectively). We administered a modified Simon ta ...[more]

PMID: 29709580

Similar Datasets

Project description:After committing an error, participants tend to perform more slowly. This phenomenon is called post-error slowing (PES). Although previous studies have explored the PES effect in the context of observed errors, the issue as to whether the slowing effect generalizes across tasksets remains unclear. Further, the generation mechanisms of PES following observed errors must be examined. To address the above issues, we employed an observation-execution task in three experiments. During each trial, participants were required to mentally observe the outcomes of their partners in the observation task and then to perform their own key-press according to the mapping rules in the execution task. In Experiment 1, the same tasksets were utilized in the observation task and the execution task, and three error rate conditions (20%, 50% and 80%) were established in the observation task. The results revealed that the PES effect after observed errors was obtained in all three error rate conditions, replicating and extending previous studies. In Experiment 2, distinct stimuli and response rules were utilized in the observation task and the execution task. The result pattern was the same as that in Experiment 1, suggesting that the PES effect after observed errors was a generic adjustment process. In Experiment 3, the response deadline was shortened in the execution task to rule out the ceiling effect, and two error rate conditions (50% and 80%) were established in the observation task. The PES effect after observed errors was still obtained in the 50% and 80% error rate conditions. However, the accuracy in the post-observed error trials was comparable to that in the post-observed correct trials, suggesting that the slowing effect and improved accuracy did not rely on the same underlying mechanism. Current findings indicate that the occurrence of PES after observed errors is not dependent on the probability of observed errors, consistent with the assumption of cognitive control account. Moreover, the PES effect appears across tasksets with distinct stimuli and response rules in the context of observed errors, reflecting a generic process. Additionally, the slowing effect and improved accuracy in the post-observed error trial do not occur together, suggesting that they are independent behavioral adjustments in the context of observed errors.

Project description:ADHD is associated with altered dopamine regulated reinforcement learning on prediction errors. Despite evidence of categorically altered error processing in ADHD, neuroimaging advances have largely investigated models of normal reinforcement learning in greater detail. Further, although reinforcement leaning critically relies on ventral striatum exerting error magnitude related thresholding influences on substantia nigra (SN) and dorsal striatum, these thresholding influences have never been identified with neuroimaging. To identify such thresholding influences, we propose that error magnitude related activities must first be separated from opposite activities in overlapping neural regions during error detection. Here we separate error detection from magnitude related adjustment (post-error slowing) during inhibition errors in the stop signal task in typically developing (TD) and ADHD adolescents using fMRI. In TD, we predicted that: 1) deactivation of dorsal striatum on error detection interrupts ongoing processing, and should be proportional to right frontoparietal response phase activity that has been observed in the SST; 2) deactivation of ventral striatum on post-error slowing exerts thresholding influences on, and should be proportional to activity in dorsal striatum. In ADHD, we predicted that ventral striatum would instead correlate with heightened amygdala responses to errors. We found deactivation of dorsal striatum on error detection correlated with response-phase activity in both groups. In TD, post-error slowing deactivation of ventral striatum correlated with activation of dorsal striatum. In ADHD, ventral striatum correlated with heightened amygdala activity. Further, heightened activities in locus coeruleus (norepinephrine), raphe nucleus (serotonin) and medial septal nuclei (acetylcholine), which all compete for control of DA, and are altered in ADHD, exhibited altered correlations with SN. All correlations in TD were replicated in healthy adults. Results in TD are consistent with dopamine regulated reinforcement learning on post-error slowing. In ADHD, results are consistent with heightened activities in the amygdala and non-dopaminergic neurotransmitter nuclei preventing reinforcement learning.

Dataset Information

Increased conflict-induced slowing, but no differences in conflict-induced positive or negative prediction error learning in patients with schizophrenia.

Publications

Increased conflict-induced slowing, but no differences in conflict-induced positive or negative prediction error learning in patients with schizophrenia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets