The Effect Of Motivated Suppression For Memory On The Validity Of Reaction Time-based Memory Detection

As a means of investigation,memory detection was widely used in criminal investigation,national security and other fields.However,countermeasures continued to emerge with the development of memory detection.Mental countermeasures,especially motivated suppression for criminal memory might affect the validity of memory detection.This study discussed the effect of motivated directly suppressed criminal memory and motivated substitute suppressed criminal memory on the validity of memory detection by using reaction time-based memory detection and event-related potential technique.The cognitive neural differences between criminal experience and false alibis were compared.The effect of motivated suppression for criminal memory on the validity of memory detection was discussed systematically.It had certain innovation and practical value.This topic will be discussed from three studies and seven experiments.Study 1,the purpose of Study 1 is to test whether motivated directly suppressed criminal information would affect the validity of memory detection.In Experiment 1,the autobiographic implicit association test was used to detect the simulated criminal experience and identity information of the subjects in the simulated crime group and the inhibition group.The result of Experiment 1 showed that there was no significant difference in the D score of simulated criminal experience test between the simulated crime group and the inhibition group,and there was also no significant difference in the D score of identity information test between the simulated crime group and the inhibition group.The result of Experiment 1 revealed that direct inhibition did not affect the validity of the a IAT.In Experiment 2,the response time-based concealed information test was used to detect the simulated crime experience and identity information of the subjects in the simulated crime group,denial group and innocent group.The result of Experiment 2 showed that the effect size of criminal experience test in the criminal denial group was significantly lower than that in the criminal group.However,the effect size of the identity test in the criminal denial group was significantly higher than that in the criminal group.The result of Experiment 2 revealed that denial of criminal experience might reduce the validity of the response time-based concealed information test,instead,denying the true identity would increase the validity of the test.Study 2,the purpose of Study 2 was to test whether motivated substitute suppressed criminal memory would affect the validity of memory detection.In Experiment 3,the response time-based concealed information test was used to detect the real identity and to explore the effect size was affected by the familiarity of the target.The result of Experiment 3 showed that the effect size of the real identity test in the false identity group was significantly lower than that in the real identity group,the effect size of the response time-based concealed information test under the familiar target stimulus condition was significantly higher than that under the unfamiliar target stimulus condition.The result of Experiment 3 revealed that false identity could reduce the validity of the test,but the familiarity of the target could improve the validity of the test.In Experiment 4,the modified response time-based concealed information test was used to detect the real identity and false identity of the subjects in the real identity group and false identity group,and to distinguish between real and false identities.The result of Experiment 4 showed that in the false identity group,the reaction time of relevant information was significantly higher than that of alternative information,and that of alternative information was significantly higher than that of irrelevant information.The result of Experiment 4 revealed that the response time-based concealed information test could effectively identify the true identity of the subjects learning the false identity and could effectively distinguish the true identity of the participants from the false identity.In Experiment 5,the response time-based concealed information test was used to detect criminal experience and false alibi in simulated crime group,false verbal alibi group,and innocent group,and to distinguish between criminal experience and alibi.The result of Experiment 5 showed that in the effect of criminal experience test,there was no significant difference between the simulated crime group and the false alibi group,the alibi group participants had a significant effect size in the criminal experience test,which was higher than the effect size of alibi test.The result of Experiment 5revealed that alibi based on oral instruction could not affect the validty of the test,the response time-based concealed information test could effectively distinguish between the participants’ criminal experience and alibis based on oral instruction.In Experiment 6,the response timebased concealed information test was used to detect criminal experience and false alibi in the alibi group based on text instruction and false alibi group based on picture instruction,and to distinguish between criminal experience and alibi.The result of Experiment 6 showed that the effect of simulated crime experience test in the alibi group based on text instruction was significantly lower than that in the simulated crime group,and there was no significant difference between the effect of false alibi test.The result of Experiment 6 revealed that alibi based on text instruction could reduce the validity of the test,the response time-based concealed information test could not distinguish between the participants’ criminal experience and alibis based on text instruction.Study 3,the purpose of Study 3 is to compare the cognitive neural differences between criminal experience and false alibis.In Experiment 7,Event-related potential technology was used to explore the cognitive processing characteristics of criminal experience and alibi under honest and deceptive conditions.The result of Experiment 7 showed that the N2 volatility induced by alibi was significantly higher than the criminal experience,and the P3 volatility induced by denial of criminal experience was significantly lower than that of admitting alibi;under different conditions,there were significant differences in the LPC volatility at FCz point induced by criminal experience and alibi.The result of Experiment 7 revealed that criminal experience and alibi were different in the stages of conflict awareness,cognitive coincidence,and execution response.In summary,this study explored the effect of motivated suppression for criminal memory on the effectiveness of the response-based criminal psychology test,revealed the mechanism of action of direct inhibition and alternative inhibition on the effectiveness of the test,and proposesd the reaction-based criminal psychology test could be used as a new method.The effectiveness of criminal psychology testing could be improved by increasing the amout of test content,optimizing the test parameters,and adopting a variety of test methods in the practice.