The Behavior And ERP Evidences Of Subliminal Affective Priming Effect With Normal And Peak Facial Expressions

In current study,we used two behavioral and an ERP experiments to investigate the subliminal affective priming effect of normal and peak facial expressions,and to find its neural mechanism.In Experiment 1,we used peak facial expressions(selected from positive(win)and negative(lose)situation)and normal facial expressions(happy and sad from POFA)as subliminal affective prime stimuli,and used neutral Greek words as targets.The independent variable is the expression intensity(peak,normal)× type(positive negative),the dependent variable is the valence evaluation of targets.In Experiment 2,we used real-life peak facial expressions(identical to Experiment1)and normal expressions(selected from positive(win)and negative(lose)situation)as primes,the happy and sad facial expressions as targets.The aim is to investigate the implicit recognition of real-life peak and normal facial expression,the independent variable was the prime(peak,normal)× The congruency type(congruent,incongruent),and the dependent variable is the performance of the valence judgment task.In Experiment 3,we combined ERP technique with paradigm in Experiment 2 to investigate neural mechanism of subliminal affective priming effect of peak and normal facial expression.The behavioral results of Experiment 1 and 2 found that normal facial expressions could be implicit recognized and induce a subliminal affective priming effect on targets word or facial expression.The specific performance pattern was: if the valence evaluation of neutral words were more positive when its prime was happy,When the targets were emotional facial expressions,the reaction time was shorter in valence congruent condition than that in congruent condition.There was no priming effect of peak facial expressions.The behavioral result of Experiment 3 was same as that of Experiment2.In Normal group,the reaction time was shorter in valence congruent condition than that in congruent condition,and the electrophysiological indices showed subliminal priming effect,the amplitude of the N250 was larger in response to congruent than to incongruent expression target.Moreover,a late positive potential(LPP),was sensitive to prime–target valence congruency,these results were restricted to those targets preceded by normal facial expression primes.The congruency effect in LPP haven’t shown in targets with peak facial expression primes,and the N250 showed a reverse congruency effect,the amplitude of the N250 was higher in incongruent trials than in congruent trials.The results show that the valence of normal facial expressions could be recognized implicitly,but the valence peak facial expression is difficult to be Implicit recognition,the evaluation and classification process of emotional valence occur in the middle and late stages.