Event-related potential correlates of spatiotemporal regularities in vision

Spatiotemporal regularities in stimulus structure have been shown to influence visual target detection and discrimination. Here, we investigate whether the influence of spatiotemporal regularities is associated with the modulation of early components (P1/N1) in event-related potentials. Stimuli consisted of five horizontal bars (predictors) appearing successively towards the fovea followed by a target bar at fixation, and participants performed a key-press on target detection. Results showed that compared with the condition where five predictors were presented in a temporally regular but spatially randomized order, target-detection times were faster and contralateral N1 peak latencies were shorter when the predictors and the target were presented with spatial and temporal regularities. Both measures were most prolonged when only the target was presented. In this latter condition, an additional latency prolongation was observed for the P1 peak compared with the conditions where the target was preceded by the predictors. The latency shifts associated with early event-related potential components provide additional support for the involvement of early visual processing stages in the coding of spatiotemporal regularities in humans.