Self-face Response Inhibition Mechanism

One’s own face possesses two properties that make it prone to grab attention: it isa face and, in addition, it is a self-referential stimulus. Self-face advantage refers toadult’s response to self-face is faster than that to other-face. Through reviewingstudies on self, it is indicated that self-face advantage would be eliminated in somesituations (like the social threat situation). The ever changing environment requireshuman beings to stop flexibly according to certain objects. To control the on-goingmotions, the ability of response inhibition is needed, which is one of the importantcomponents of executive function. Response inhibition refers to inhibit behaviorswhich are no longer suitable or appropriate. Accordingly, we intended to explore theresponse inhibition of self-related information, taking self-face for example.Stop-signal paradigm is thought to be a more pure test to study responseinhibition. This paradigm is consisted of a go task and a stop task. Participants areinstructed to press the button selectively (go task), when they occasionally hear astop-signal which occurred shortly after the go stimulus, they should try to withholdtheir motor response (the stop task).The present study employed the stop-signal paradigm and used the self-face andother-face as experimental materials. It was hypothesized that the self-face advantagewas mediated by the signal and would be more significant in the impulsive condition.In addition, response inhibition of self-face would be better than that of other-face. Toconfirm the assumption, a behavioral experiment (experiment1) and an ERPexperiment (experiment2) were taken.The results of experiment1found that there’s no significant difference betweenself-face RTs and other-face RTs in the go task. The signal-response RTs of self-facewere significant faster than that of other-face in the unsuccessful stop trials. Thesignal-stop RTs of self-face were significant faster than that of other-face in thesuccessful stop trials. We suggested that the self-face impulsivity was stronger so that more inhibition effort is needed to withhold it.In experiment2, the ERP technical method was used to explore the brainmechanism of self-face response inhibition. The results found, though no differencewas found between self-face RTs and other-face RTs, the frontal-central N2amplitudeof self-face was reduced significantly than that of other-face and the parietal-occipitalP300amplitude of self-face was larger than that of other-face in the go task. Therewas a more negative slow in the frontal-central area wave triggered by self-face in thesuccessful stop trials. Unsuccessful inhibition of self-face produced larger P300amplitudes.In a word, the present study confirmed that the self-face advantage was mediatedby the signal. Self-face was more impulsive in the unsuccessful inhibiting trials andthis impulsivity triggered larger P300amplitude. It was also examined that theresponse inhibition was affected by the self-face advantage, which triggered morenegative slow wave, suggesting that more cognitive resource was needed to inhibitingthe response to self-face.