Abstract
Emotional stimuli like emotional faces have been frequently shown to be temporally overestimated compared to neutral ones. This effect has been commonly explained by induced arousal caused by emotional processing leading to the acceleration of an inner-clock-like pacemaker. However, there are some studies reporting contradictory effects and others point to relevant moderating variables. Given this controversy, we aimed at investigating the processes underlying the temporal overestimation of emotional faces by combining behavioral and electrophysiological correlates in a temporal bisection task. We assessed duration estimation of angry and neutral faces using anchor durations of 400 ms and 1600 ms while recording event-related potentials. Subjective ratings and the early posterior negativity confirmed encoding and processing of stimuli’s emotionality. However, temporal ratings did not differ between angry and neutral faces. In line with this behavioral result, the Contingent Negative Variation (CNV), an electrophysiological index of temporal accumulation, was not modulated by the faces’ emotionality. Duration estimates, i.e., short or long responses toward stimuli of ambiguous durations of 1000 ms, were nevertheless associated with a differential CNV amplitude. Interestingly, CNV modulation was already observed at 600–700 ms after stimulus onset, i.e., long before stimulus offset. The results are discussed in light of the information-processing model of time perception as well as regarding possible factors of the experimental setup moderating temporal overestimation of emotional stimuli. In sum, combining behavioral and electrophysiological measures seems promising to more clearly understand the complex processes leading to the illusion of temporal lengthening of emotional faces.
Phasic brain activity related to the onset of rapid eye movements during rapid eye movement sleep: study of event-related potentials and standardized low-resolution brain electromagnetic tomography
