Motivational Deficits in Schizophrenia Are Associated With Reduced Differentiation Between Gain and Loss-Avoidance Feedback in the Striatum.
BACKGROUND
The current study was designed to test the hypothesis that motivational deficits in schizophrenia (SZ) are tied to a reduced ability to differentially signal gains and instances of loss-avoidance in the brain, leading to reduced ability to form adaptive representations of expected value.


METHODS
We administered a reinforcement learning paradigm to 27 medicated SZ patients and 27 control subjects in which participants learned three probabilistic discriminations. In regions of interest in reward networks identified a priori, we examined contrasts between trial types with different expected values (e.g., expected gain-nonmonetary) and between outcomes with the same prediction error valence but different experienced values (e.g., gain-loss-avoidance outcome, miss-loss outcome).


RESULTS
Both whole-brain and region of interest analyses revealed that SZ patients showed reduced differentiation between gain and loss-avoidance outcomes in the dorsal anterior cingulate cortex and bilateral anterior insula. That is, SZ patients showed reduced contrasts between positive prediction errors of different objective values in these areas. In addition, we observed significant correlations between gain-loss-avoidance outcome contrasts in the ventral striatum and ratings for avolition/anhedonia and between expected gain-nonmonetary contrasts in the ventral striatum and ventromedial prefrontal cortex.


CONCLUSIONS
These results provide further evidence for intact prediction error signaling in medicated SZ patients, especially with regard to loss-avoidance. By contrast, components of frontostriatal circuits appear to show reduced sensitivity to the absolute valence of expected and experienced outcomes, suggesting a mechanism by which motivational deficits may emerge.
['Waltz|James A|JA|', 'Xu|Ziye|Z|', 'Brown|Elliot C|EC|', 'Ruiz|Rebecca R|RR|', 'Frank|Michael J|MJ|', 'Gold|James M|JM|']
D000328:Adult D001931:Brain Mapping D003342:Corpus Striatum D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009042:Motivation D012201:Reward D012559:Schizophrenia D012565:Schizophrenic Psychology
Reinforcement learning Reward Anterior insula Ventral striatum Avolition fMRI