The Modulation Function Of Arousal On Motor Interference Effect And EEG Microstate Anaylsis Based On High And Low Effect Size Grouping

Motor interference effect is a phenomenon that responses to dangerous objects are slower than those to safe objects in the state of motor preparation.Previous research using ERP technology found that delayed responses in dangerous condition were associated with more positive parietal P3 component,that is,great attentional resources were allocated to evaluate the level of danger(i.e.,negative valence).However,compare to the neutral valence and medium arousal attributes for safe objects,the valence is more negative and the arousal attribute is higher for dangerous objects.Obviously,arousal covaried with valence in this research.Together with previous studies in which the P3 amplitude was found to be increased along with higher arousal level in the parietal lobe.Therefore,more positive parietal P3 amplitudes might also be influenced by a high arousal level in the dangerous condition.In order to solve the issues,the current research investigates the influence of the two factors on the motor interference effect by systematically manipulating valence and arousal levels of target stimuli.The current study includes two experiments to investigate the motor interference effect from cognitive processing mechanism and individual differences perspective,respectively.Experiment 1 used a motor priming paradigm mixed with a Go/NoGo task and manipulated the valence(negative,neutral and positive)and arousal(medium and high)of target stimuli to investigate modulation effect of arousal on the motor interference effect.Analysis of the behavioral results identified a significant motor interference effect(longer reaction times in the negative valence condition than the neutral valence condition)and an insignificant difference between the negative and positive valence conditions at the medium arousal level.However,the effect size(increment of RTs)of the motor interference effect enlarged and the difference between the positive and neutral valence conditions diminished at the high arousal level.The ERP results further identified more positive centroparietal P3 amplitudes for the negative valence condition than for the neutral and positive valence conditions,and more positive centroparietal P3 amplitudes for the neutral valence condition than for the positive valence condition at a high arousal level.However,the inverse results were identified at the medium arousal level.Specifically,less positive centroparietal P3 amplitudes were identified at the negative valence condition than the neutral and positive valence conditions,and the difference of centroparietal P3 amplitudes between neutral and positive valence conditions diminished at the medium arousal level.Experiment 2 divided the subjects into a high inhibition group and a low inhibition group according to the effect size of the motor interference effect(in the top 27% versus in the bottom 27%)which was calculated based on the behavioral results of the experiment 1.The resting state EEG microstate were separately analyzed in the high and medium arousal levels.For analyzing,peak values of topographic map intensity(the standard deviation of voltage values for all electrodes at each time point)were calculated.Then,the Atomic & Agglomerate Hierarchical Clustering(AAHC)clustering analysis was used for clustering all of the topographic maps into 4 microstates.Finally,the characteristic indexes such as duration,occurrence frequency and coverage rate of the different kind of microstates were counted.The results found that the class C appeared significantly more frequent in the high inhibition group than the low inhibition group at the high arousal level.However,all indices did not reach significant at the medium arousal level.The study draws the following conclusions:1.Arousal modulates the motor interference effect from dangerous objects.The behavioral results suggest that negative valence stimuli may interfere with a prime elicited motor preparation more strongly at the high arousal level than at the medium arousal level.The ERP results further indicate that the effect size of the behavioral motor interference effect was increased because subjects are more sensitive to the negative valence stimuli at the high arousal level than to those at the medium arousal level.Furthermore,the motor interference effect is related to the negative valence rather than emotionality of the target stimuli because different result patterns are emerged between the positive and negative valence conditions.2.High and low inhibition ability are associated with executive function.The results of the microstate analysis show that the subjects with high inhibition ability activate executive function related brain networks less frequent than the subjects with low inhibition ability in resting state.The results suggest that subjects with high inhibition ability are equipped with strong executive control ability and are unnecessary to activate the related brain network frequently.