A Study On The Categorical Perception Of Facial Expressions Of Depression Tendency Of Undergraduates

Depression is a relatively common mental illness,with a high prevalence.Depression patients can not correctly identify and respond to changes in the facial expressions of others in social processes,which may be associated with significant social barriers in depressive patients.(Kohler,Hoffman,Eastman,Healey,& Moberg,2011),social deficits are important causes of depression formation and persistence(Joormann & Gotlib,2006),while emotional facial expression processing is impaired May lead to social defects.Behavioral literature investigating the emotional processes of depressed populations(ie,single-phase and bipolar depression)states that depression subjects exhibit interrupted emotional processing compared to health control,with a weak response and / or delayed response latency as an indicator The However,most of the current studies focused on patients with severe depression,and the response bias and sensitivity to mood stimulation in patients with depression can not be a good predictor,and it is not possible to determine the information processing of defects in patients with depression Position,the current research using experimental materials and research paradigms did not yield a uniform result.Therefore,in this study,gradient facial stimulation and category perception experiment paradigm were used to investigate the differences in facial expression response bias and sensitivity of depression tendency of undergraduates compared with normal population.This study consisted of three experiments: experimental depressive tendencies of college students' response to gradient facial expressions and perceived sensitivity to change.Experiment 2 on the basis of experiment one to explore the bias in the gradient of the facial expression of the tendency of the tendency of college students to respond to the gradient of the pure facial expression bias perception perception sensitivity.The differences in amplitude and latency of N2 and P3 waves in 40%,70%,and 100% of emotional episodes were analyzed in the depression and control groups.The results are as follows:1.The depression group and the control group showed a high correct rate of close to the expression of the sad expression in distinguishing between anger-sadness and pleasure-sad expression continuum,but the difference between the two groups was not significant.Using the continuum from the neutral expression to the complete emotional expression,the anger-sad expression continuum was separated and found that the depression group showed a higher correct rate when the anger expression in the class was found compared with thecontrol group,Indicating that there were significant differences in the expression of anger between the two groups,compared with the control group,the depression group is more sensitive to anger expression.2.In the recognition task,the depression group showed a bias in response to negative facial stimuli,compared to the control group,avoids recognition of happy expression,and showed a reaction to anger expression on anger-sad expression continuum,But there was no difference in sensitivity between the two groups.In the neutral-episode continuum,the depression group also showed the same response bias: compared with the control group,in the neutral-anger continuum,the depression group identified the blurred expression as anger,while in the neutral-happy Expression continuum is more fuzzy expression to identify the neutral,to avoid recognition as happy.3.In the recognition of response,both the expression-expression continuum and the neutral-expression continuum,the response to the continuum class boundary will be significantly increased,indicating the existence of the category boundaries,but the difference between groups Significantly.4.EEG experiments show that the amplitude of N2 and P3 is affected by the intensity of gradient expression and is not sensitive to weak(40%)emotional expression,and both subjects are induced by complete(100%)emotional expression Larger amplitude of ERP components.In the different intensity of sadness and anger expression,the depression group showed greater than the control group N2 and P3 volatility,and happy expression is not obvious to show this difference,indicating that the depression group is more sensitive to negative expression.There was no significant difference in the latency of N2 and P3 components,indicating that the cognitive phases of the two groups were consistent in the processing of emotional expressions.