Irrelevant task suppresses the N170 of automatic attention allocation to fearful faces

Abstract

Recent researches have provided evidence that stimulus-driven attentional bias for threats can be modulated by top-down goals. However, it is highlight essential to indicate whether and to what extent the top-down goals can affect the early stage of attention processing and its early neural mechanism. In this study, we collected electroencephalographic data from 28 healthy volunteers with a modified spatial cueing task. The results revealed that in the irrelevant task, there was no significant difference between the reaction time (RT) of the fearful and neutral faces. In the relevant task, we found that RT of fearful faces was faster than that of neutral faces in the valid cue condition, whereas the RT of fearful faces was slower than that of neutral faces in the invalid cue condition. The N170 component in our study showed a similar result compared with RT. Specifically, we noted that in the relevant task, fearful faces in the cue position of the target evoked a larger N170 amplitude than neutral faces, whereas this effect was suppressed in the irrelevant task. These results suggest that the irrelevant task may inhibit the early attention allocation to the fearful faces. Furthermore, the top-down goals can modulate the early attentional bias for threatening facial expressions.