Visual temporal window of integration as revealed by the visual mismatch negativity event-related potential to stimulus omissions.

We studied whether, similarly to the auditory modality, short-period temporal integration processes occur in vision. Event-related potentials (ERP) were recorded for occasional stimulus omissions from sequences of patterned visual stimuli. A posterior negative component emerged only when the constant stimulus onset asynchrony (SOA) was shorter than 150 ms. This upper limit is comparable with the duration of the temporal window of integration observed in the auditory modality (including experiments studying the effects of stimulus omissions). Parameters of the posterior negativity were highly similar irrespective of whether the stimuli were task-relevant or not (Experiment 1). Thus, we identified this potential as the visual mismatch negativity (vMMN) component, which reflects task-independent detection of violating regularities of the stimulation. vMMN was followed by an anterior positivity (the P3a), indicating attentional shifts induced by the stimulus omissions. In Experiment 2, a posterior negativity similar to that observed in Experiment 1 emerged after the termination of short trains of stimuli, again only when the SOA was shorter than 150 ms. These results support the notion of a temporal integration window in the visual modality, the duration of which is between 150 and 180 ms.