Human electrophysiological examination of buildup of the precedence effect.

Event-related potential correlates of the buildup of precedence effect were examined. Buildup is a type of precedence effect illusion in which perception changes (from hearing two clicks to hearing one click) during a click train. Buildup occurs faster for right-leading than left-leading clicks. Continuous click trains that changed leading sides every 15 clicks were presented. Event-related potential N1 amplitudes became smaller with click train for right-leading only. N1 latency decreased with click trains. Mismatch negativity was seen after lead-lag sides were changed. When the perceived change differed in location (left-to-right), mismatch negativity peaked earlier than when the perceived change differed in location and number of clicks (right-to-left). Results suggest that buildup relates to: N1 refractoriness, event-related potential 'lead domination' and mismatch negativity differences.