Subliminal Fearful Face Modulates Early Visual Processing

Fear expression is a kind of important social information. Recent studies have found that fear expressions modulate the processing of visual stimuli in different spatial frequency. The purpose of this study was to explore the possible modulaton of early visual processing of different spatial frequency stimulus by subliminal fearful face, and its mechanism. The experiment begins with double pictures of same faces on both sides of central fixation, which are backward masked by a mosaic picture rapidly, then in the center of the screen presents high spatial frequency or low spatial frequency gabor, the task of subjects is to detect tilt gabor.Results found:Behavior results:(1) when presenting expression of upright face, the detection of high spatial frequency gabor after upright fearful face was more slowly, and the discriminability decreased; the detection of low spatial frequency gabor after upright fearful face was more rapidly, and the discriminability increased.(2) when presenting inverted face,similar effects of upright face condition were not found. The presentation of inverted fearful face haven’t change subjects response performance of different spatial frequency gabors.ERP results:(1) The presentation of upright fearful face, compared to upright neutral face decreased high spatial frequency stimulus evoked N1 amplitude(2) The presentation of upright fearful face, compared to upright neutral face increased high spatial frequency stimulus evoked P1 amplitude(3) When the face was presented inverted, P1/N1 effect similar to upright face conditions was not found. There is no significant difference of the P1/N1 amplitude evoked by high spatial frequency gabors and low spatial frequency gabors presented after inverted neutral or inverted fearful face.