The time course of local coherence effects: Evidence from self-paced reading times and event-related potentials

In sentences like ``The coach smiled at the player tossed a frisbee,'' the string ``the player tossed a frisbee'' cannot be an active subject-verb-object (SVO) clause given the preceding context; yet, comprehenders seem to entertain this incorrect parse, at least momentarily. Behaviorally, this momentary mis-parse is expressed as greater difficulty during and after the SVO phrase is read.This phenomenon, called local coherence effect, has important implications for sentence processing theories that treat grammar as a strict filter during incremental sentence processing: Under such a strict filter, local coherence effects should never occur. Several studies report the existence of local coherence effects in languages like English, German, and Hindi, but one question remains unanswered: at what moment is the local coherence effect triggered, and how quickly does grammar override the mis-parse? We investigate the time course of local coherence effects through two relatively large-scale experiments in German (self-paced reading and EEG). Our data suggest that local coherence effects, indexed by longer reading time and more positive P600, is triggered very early, as soon as the locally coherent phrase is read. However, the locally coherent parse does not linger, that is, it does not continue to cause processing difficulty. A broader implication of our findings is that although grammar is not a strict a-priori filter, it rapidly steps in to correct incremental sentence structure building.