The time course of local coherence effects in German: 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 when the SVO chunk is read. This phenomenon, called a 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. Although several studies report the existence of local coherence effects, one question remains unanswered: at what moment are local coherence effects triggered, and how quickly - if at all - does grammar override the mis-parse? We investigate the time course of local coherence effects through two experiments in German (self-paced reading and EEG). Our data suggest that the local coherence effect, indexed by longer reading times and a more positive P600, was triggered as soon as the locally coherent chunk was read. However, the locally coherent parse did not linger; it did not continue to cause processing difficulty. Our results are compatible with self-organized parsing and versions of good-enough processing. Our results do not support accounts in which local coherence effects are caused by uncertainty about previous input or by a complete breakdown of algorithmic parsing. A broader implication of our findings is that although grammar is not a strict a-priori filter, it can step in rapidly to correct incremental structure building.