Characteristics Of Money Reward Processing In Children With High Schizotypal Traits In Grades 3-6

Schizotypy,as a personality performance in the early stage of schizophrenia,refers to a group of temporarily stable personality structures similar to the symptoms of schizophrenia observed in the general population.The defect of reward processing is a core feature of schizophrenia.A series of emotional and motivational disorders in patients with schizophrenia have been clinically confirmed.But there is no consistent conclusion on whether reward processing is impaired in individuals with high schizotypy.In recent years,some researchers began to use questionnaires or behavioral experiments to explore the reward processing in non-clinical samples or high-risk groups with schizophrenia spectrum disorders,but there is a lack of research using the event-related potentials(ERPs).The reward processing can usually be divided into two stages: reward anticipation and outcome evaluation.In view of the high temporal resolution of ERP technology,which can capture the EEG components in different processing stages of reward anticipation and outcome evaluation,the present study used ERP technology to investigate the characteristics of reward processing in children with high schizotypy.Specifically,in this study,Schizotypal Personality Questionnaire-Child(SPQ-C)was used to measure the schizotypal traits of 350 primary school students in grades 3-6.The high schizotypal trait group(n = 30)and the control group(n =30)were distinguished,and then the two groups of children completed the monetary incentive delay task(MID)and a simple gambling task.This paper explores the reward processing characteristics of children with high schizotypy from two aspects of reward anticipation and outcome evaluation.In Experiment 1,the MID task was used to compare the differences in reward anticipation between the two groups.A mixed experimental design of 2(Group: high schizotypal trait group vs.control group)× 3(Cue Type: reward anticipation cue vs.loss anticipation cue vs.no-reward anticipation cue)was adopted.The results of questionnaire and behavior showed that there were no significant differences between the two groups in the dimensions of abstract anticipatory pleasure,abstract consummatory pleasure,contextual anticipatory pleasure,contextual consummatory pleasure and the total score of TEPS.The correct rates under reward and loss cues were significantly higher than that of no-reward cue.The reaction time of high schizotypal trait group was significantly shorter than control group.The EEG results showed that in cue-evaluation stage,there was no significant difference in cue-P3 amplitude between the two groups.In motor-preparation stage,the results of late CNV(Contingent Negative Variation)showed that under the reward cue,the high schizotypal trait group evoked greater CNV amplitude than control group.In the stage of feedback anticipation,the SPN(Stimulus-Preceding Negativity)amplitudes of children in the control group had no significant differences under the three conditions,while in high schizotypal trait group,the amplitudes of SPN evoked by reward and loss cues were larger than no-reward cue.In Experiment 2,a simple gambling task was used to compare the differences in outcome evaluation between the two groups.A mixed experimental design of 2(Group: high schizotypal trait group vs.control group)× 2(outcome magnitude: 9 vs.99)× 2(outcome valence: gain vs.loss)was adopted.The results of questionnaire and behavior showed that there were no significant differences between the two groups in the total score and each dimension of TEPS.There were no significant differences in reaction time and risk-avoidant rate between the two groups.The EEG results showed that for FRN raw wave,the FRN amplitude of high schizotypal trait group was significantly larger than control group.Under the conditions of small loss and large gain,high schizotypal trait group evoked greater FRN amplitude than control group.In high schizotypal trait group,small loss evoked larger FRN amplitude than small gain.In control group,the FRN of small and large loss were more negative than gain.For the difference waves of FRN,in large magnitude condition,the amplitude of FRN difference wave evoked by control group was significantly larger than high schizotypal trait group.The amplitude of Fb-P3 in control group was significantly larger than high schizotypal trait group.In conclusion,this study draws the following conclusions: In the stage of reward anticipation,high schizotypy children have stronger motivation for reward cues.In the stage of outcome evaluation,the neuro-sensitivity of children with high schizotypy to large reward is reduced,and the attention resources are impaired in high schizotypy children.Future research can prove that children with schizotypy have abnormal motivation in various aspects by distinguishing between positive and negative schizotypy,distinguishing individuals at different stages of schizophrenia spectrum disorder,distinguishing between monetary rewards and social rewards and using different experimental paradigms.