Dissociating brain responses to syntactic and semantic anomalies: Evidence from event-related potentials

Two experiments investigated the influence of anomaly type and presentation rate on the occurrence and appearance of the event-related brain potentials (ERPs) known as the N400 and P600. In Experiment 1, sentences containing either a syntactic anomaly, a semantic anomaly, or a compound syntactic and semantic anomaly were presented at the rate of 1000 ms per word. Consistent with previous findings, syntactic anomalies elicited a P600, while semantic anomalies elicited an N400. Compound anomalies evoked an N400-P600 waveform complex. Experiment 2 investigated the effect of presentation rate on ERPs using the syntactic anomaly materials from Osterhout and Holcomb (1992: Experiment]) at the 650 ms SOA from the original study and a new 1000 ms SOA. Although the amplitude and latency of the P600 waveform differed slightly between the two presentation rates, reliable P600s a ere found at both the 650 and the 1000 ms SOA. (C) 1998 Academic Press.