Research On ERP Component Of Antonym Comparison In Case Detection

Aim: To test the feasibility of using antonyms as stimulus materials for criminal psychological test,to explore the difference of EEG changes when subjects see the stimulus that conform to the case information and the antonyms that do not conform to the case information.And test whether the subjects' reaction to the stimulus words is the same with reaction to the antonyms.Method:This study uses the experimental method,the subjects were divided into two groups: the involved group and the innocent group.The involved group simulated the case to obtain the information related to the case.In first experiment,taking 2(stimulus material:stimulus word / antonym)X2(subject type:involved group / innocent group)as the experimental design,32 college students were randomly divided into two groups: the involved group and the innocent group.Before the experiment,the involved group conducted case simulation to obtain the relevant experience and memory of the simulated case,so as to distinguish the innocent group.The second experiment continued on the basis of the first experiment,taking 2(stimulus material: stimulus word / antonym)X2(response type: honest response / deception response)as the experimental design in the group.Both the two experiments were used to collect and record ERP.Results: Experiment 1: when the group involved in the case saw the stimulus words that were consistent with the case,it produced larger P3 and late positive components,and when it saw the antonym,it also produced certain P3 and late positive components,but it was smaller than when they saw the stimulus words,and the P3 [f(1,30)= 5.614,P = 0.024] and late positive components [f(1,30)= 5.524,P = 0.025] produced by the stimulus words and antonyms were significantly different.The P3 and late positive components of the innocent group were not significant when they saw the stimulus words and antonyms,and the difference was not significant.Experiment 2: on the behavioral data,under the condition of honest response,the accuracy of the answer to the stimulus words is significantly higher than that to the antonyms [f(1,15)= 7.558,P = 0.015];under the condition of the stimulus words,the accuracy of the honest response is significantly higher than that to the deception [f(1,15)= 26.010,P =0.000];under the condition of the antonyms,the accuracy of the honest response and the deception response was not significant.In EEG data,P3 of stimulus word was significantly higher than that of antonym [f(1,15)= 10.337,P = 0.006] in honest response,and there was no significant difference in P3 of stimulus words and antonym in deceptive response.In terms of the late positive component,under the condition of stimulus words,the late positive componentof honest response is significantly greater than that of deceptive response [f(1,15)= 7.567,P =0.015],and under the condition of the same antonym,the late positive component of honest response is significantly less than that of deceptive response [f(1,15)= 6.747,P = 0.020].In the condition of honest response,the late positive component of stimulus words is significantly greater than that of antonym [f(1,15)= 15.554,P = 0.001].In the deceptive reaction,the late positive component of stimulus word is significantly smaller than that of antonym [f(1,15)=13.828,P = 0.002],.Conclusions: The stimulus words and antonyms have a better detection effect on the innocent group and the involved group.The EEG of the innocent group is consistent when they see the just words and the opposite words,while the involved group has a big difference when they see the positive and negative words,so they can distinguish the involved group and the innocent group.The stimulus words and antonyms can test the honest and deceptive answers of the group involved in the case,and reflect certain behavior and thinking characteristics in both behavioral data and EEG data.When the person involved answers "yes" to the description of the stimulus word of the case(i.e.the honest answer of the stimulus word)and "no" to the description of the antonym of the case(i.e.the honest answer of the antonym)are not consistent.