Cognitive Neuroscience

Abstract: We investigated the relative time courses of the accessibility of semantic and syntactic information in speaking and comprehension via event-related brain potentials (ERPs). Native German speakers either viewed a series of pictures (tacit picture naming experiment) or heard a series of nouns (listening experiment) and made dual choice go/nogo decisions based on each item's semantic and syntactic features. N200 peak latency results indicate that access to meaning has temporal precedence over access to syntactic information in both speaking ( 80 ms) and comprehension ( 70 ms), and are discussed in the context of current psycholinguistic theories.

Abstract: 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

1. 1. 1. 1. 1. 1. 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 1) 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 were found at both the 650 and the 1000 ms SOA.

Abstract: Event-related potentials (ERPs) were recorded from 13 scalp electrodes while subjects read sentences, some of which contained violations of number or gender agreement. Subjects judged the acceptability of sentences in Experiments 1 and 2 and passively read sentences in Experiment 3. In Experiment 1, violations of subject-verb number, reflexive-antecedent number, and reflexive-antecedent gender agreement elicited a widely distributed positive-going wave (P600). Subject-verb agreement violations also elicited a left-hemisphere negativity. In Experiment 2, personal pronouns that mismatched in gender with the subject noun elicited a P600, but only when subjects judged such sentences to be unacceptable. Semantically anomalous words elicited an enhanced N400 component. In Experiment 3, subject-verb number disagreement elicited a P600 and semantic anomalies elicited an enhanced N400. ERPs to reflexive-antecedent agreement violations did not differ from those to controls. We evaluate the speculation that agreement between sentence constituents reflects syntactic constraints rather than semantic or discourse factors.