Reward Representation Maintenance In Schizophrenia Patients And Individuals With Schizotypal Traits

The anticipatory anhedonia,which means the decrease in pleasure experienced when predicting or pursuing reward incentives that may be obtained in the future,is the core component of the negative symptoms of schizophrenia.The maintenance of reward representation is the key process of inducing the expectant pleasure experience.Previous studies have found that there are defects in the maintenance of reward representation in schizophrenia patients.However,few previous studies have examined this process and the underlying neural mechanism is still unclear.Guided by the emotional motivation integration model,this study used reward representation maintain task to explore the maintenance process of reward representation in schizophrenia and its high-risk population(schizophrenic personality traits)by two experiments,in order to explain the symptoms of anticipatory anhedonia.In Experiment 1,the behavioral performance of schizophrenia patients(n=28),schizophrenic personality trait subjects(n=29),and healthy controls(n=31)during the maintenance of reward representation were compared,and it was found that compared with healthy controls,patients with schizophrenia had a highest mismatch ratio in the evaluation of emotion when the reward representation was maintained.There was no significant difference between schizotypal individuals and controls during the maintenance of reward representations in the number of pressing and in the mismatch ratio of the emotional evaluation.In experiment 2,using the same experimental paradigm and functional magnetic resonance imaging,the brain activities of 26 individuals with schizotypal traits and of 29 controls were analyzed.It was found that during the maintenance phase,compared with the control group under the condition of maintenance,the activation of the left anterior cingulate gyrus,the right insula,and the right putamen is weaker in the schizotypy.Social anhedonia is associated with the activation of the left dorsolateral prefrontal lobe during maintenance.During the anticipation phase,the right precuneus,bilateral caudate nucleus,right anterior cingulate gyrus,middle frontal gyrus and other regions that were activated significantly higher in schizotypy than that in the healthy control group in maintenance condition.In conclusion,the abnormal maintenance processing of reward representations in schizophrenia played an important role in the appearance of anticipatory anhedonia.While the schizotypy had not shown behavioral deficits,the neuroimaging evidences supported that maintenance of reward representations may be impaired.The deactivation of the left dorsolateral prefrontal cortex was associated with social anhedonia,suggesting that the dorsolateral prefrontal cortex plays a critical role in the maintenance of reward representations among schizophrenia spectrum disorders.This research may help us understand more about the anhedonia symptom among schizophrenia spectrum disorders,and it will also benefit for intervention and treatment of schizophrenia.