Mild Depression And Uncertain Feedback Effect On The Evaluation Of The Results

In everyday life,people often need to make decision in uncertain environment and adjust their future behavior according to the result of the decisions.In recent years,many researchers have utilized event-related potentials and simple gambling task and time estimation task to investigate the processing of outcome evaluation.They found that the Feedback-Related Negativity(FRN)were the most important components related to the feedback processing.The FRN is a negative deflection that Occurs at about 250-300 ms interval post feedback onset.At present,there are a lot of researches bout individual differences and uncertainty in the FRN,but there is no unanimous conclusion.In order to investigate these questions,we used a modulated time estimate task in this study.In the experiment one,the FRN results of depression group and control group will be contrasted.Meanwhile,feedback stimulus is divided into three kinds,positive feedback,negative and neutral feedback.The second experiment by setting a different probability of rewards to examine the influence of reward probabilistic on neutral feedback evaluation.The results of experiment one showed that mild depression will affect the outcome.In high BDI group,there is no significant difference between the FRN amplitude in the negative feedback and neutral feedback.However,FRN in neutral feedback was significantly greater than the negative feedback in low BDI group.The experiment two was conducted to test whether the reward probabilities will influence the outcome evaluation.Unexpected feedback within the FRN amplitude was significantly greater than expected amplitude of the FRN.Probability effect also influenced the evaluation of neutral feedback,specifically,the neutral feedback FRN in high-reward probability condition was significantly greater than that in the low reward probability condition.