TEMPORAL STRUCTURE OF SYNTACTIC PARSING - EARLY AND LATE EVENT-RELATED BRAIN POTENTIAL EFFECTS

Event-related brain potentials (ERPs) were recorded from participants listening to or reading sentences that were correct, contained a viola tion of the required syntactic category, or contained a syntactic-cate gory ambiguity. When sentences were presented auditorily (Experiment 1 ), there was an early left anterior negativity for syntactic-category violations, but not for syntactic-category ambiguities. Both anomaly t ypes elicited a late centroparietally distributed positivity. When sen tences were presented visually word by word (Experiment 2), again an e arly left anterior negativity was found only for syntactic-category vi olations, and both types of anomalies elicited a late positivity. The combined data are taken to be consistent with a 2-stage model of parsi ng, including a 1st stage, during which an initial phrase structure is built and a 2nd stage, during which thematic role assignment and, if necessary, reanalysis takes place. Disruptions to the 1st stage of syn tactic parsing appear to be correlated with an early left anterior neg ativity, whereas disruptions to the 2nd stage might be correlated with a late posterior distributed positivity.