Enhanced facial EMG activity in response to dynamic facial expressions.

The suggestion that dynamic facial expressions of emotion induce more evident facial mimicry than static ones remains controversial. We investigated this issue by recording EMG from the corrugator supercilii and zygomatic major. Dynamic and static facial expressions of anger and happiness were presented. Dynamic presentations of angry expressions induced stronger EMG activity from the corrugator supercilii than static presentations, while dynamic presentations of happy expressions induced stronger EMG activity from the zygomatic major compared to static presentations. These results indicate that dynamic facial expressions induce facial EMG activity interpretable as facial mimicry more evidently than static expressions.