Cerebral patterns of attentional habituation to emotional visual stimuli.

Attentional habituation in response to emotional stimuli, an aspect of the interaction between cognitive and emotional processes that has received scant attention, was investigated. Event-related potentials were recorded using a 60-electrode array from 25 participants who attended to 120 presentations of three different picture types: emotionally negative (S-), positive (S+), and neutral (SO). The affective content of the stimulation was assessed, through questionnaires, by the participants themselves. N1 showed different patterns of habituation as a function of the stimulation: amplitudes indicated that S- was more resistant to habituation than SO and S+. This pattern, which reflects a greater capacity of S- to attract and maintain the participant's attention, is interpreted as a manifestation of the "negativity bias," a phenomenon that reflects an evolution-favored set of mechanisms that facilitate a rapid and intense response to aversive events.