Stimulus novelty and emotion perception: the near absence of habituation in the visual cortex.

In rapid serial visual presentation of pictures, an early event-related brain potential component shows enlarged negativity over occipital regions for emotional pictures compared with neutral pictures. The present study examined whether the processing of emotional target pictures varies as a function of stimulus repetition. Accordingly, pictures of erotica, neutral contents, and mutilations were repeatedly presented (90 times) while the electroencephalogram was recorded with a 129 dense sensor array. As in previous studies, emotional pictures were associated with a larger posterior negativity than neutral pictures. Furthermore, differential emotion processing did not vary as a function of stimulus repetition and was similarly expressed across blocks of picture presentation. These findings suggest the near absence of habituation in differential emotion processing during perceptual processing.