Microexpressive Facial Actions as a Function of Affective Stimuli: Replication and Extension

Abstract

The effects of communicative intent and stimulus affectivity on facial electromyogrqphic (EMG) activity were investigated. Subjects viewed slides of pleasant, neutral, or unpleasant social or nature scenes under no instruction, inhibit-expression instructions, and amplify-expression instructions. Results revealed that facial EMG activity was highest in the amplify and lowest in the inhibit condition; EMG activity over the corrugator supercilii region varied as a function of the affective valence of the stimuli regardless of instructional condition; and facial EMG activity did not differ when subjects were exposed to slides of nature versus social scenes that were matched for rated pleasantness. These results suggest that facial efference can be altered by both affective and communicative processes even when it is too subtle to produce a socially perceptible facial expression.