Repeated exposure makes attractive faces more attractive: Neural responses in facial attractiveness judgement.

Facial attractiveness affects social interaction and decisions. Previous studies have shown people automatically judge facial attractiveness upon first impression. However, how facial attractiveness changes with repeated exposure is still unknown. The event related potential technique was used to examine the underlying neural processing of the repeated exposure effect on facial attractiveness. The results showed that for high attractive faces, attractiveness judgement increased significantly with repeated exposure, underpinned by smaller N170 and larger LPP. The duration of microstate C was negatively correlated with attractiveness judgement. Source location revealed that with repeated exposure, microstate C activated the supramarginal gyrus and superior temporal gyrus, which are related to attention and emotion processing, respectively. These results suggest repeated exposure affects the cognitive and affective brain systems when processing high attractive faces. Concerning middle attractive faces, with repeated exposure, these were also seen as more attractive, yielding larger EPN. The occurrence of microstate C was positively correlated with attractiveness judgement. Source location revealed that microstate C during repeated exposure activated the middle frontal gyrus. These results indicate repeated exposure affects the emotional brain system when processing middle attractive faces. Our findings suggest the cognitive and affective brain systems play an important role in the changes of facial attractiveness judgement.