An EEG investigation of the mechanisms involved in the perception of time when expecting emotional stimuli.

The main goal of the current study was to identify the electrophysiological signatures of the mechanisms involved in the perception of time when expecting positive, neutral or negative stimuli that have equal arousal levels. Participants were asked to compare the duration of time intervals with a 2-sec reference interval. The color of circles marking a given comparison interval signaled the valence of the upcoming stimulus to be presented, each stimulus being drawn from the International Affective Picture System (IAPS). The behavioral data suggest that time distortion can be induced by the expectation of stimuli with different valences and that expecting a negative stimulus leads to an overestimation of time. The electrophysiological data, more specifically the N150, N200, LPP and CNV components, provide evidence of the implication of attentional mechanisms and possibly strategic adjustments of cognitive control for time perception.