Time course of word identification and semantic integration in spoken language

Cyma Van Petten, Seana Coulson, Susan Rubin, Elena Plante, and Marjorie Parks

Journal of Experimental Psychology: Learning, Memory and Cognition 25:394-417 (1999)

The minimum duration signal necessary to identify a set of spoken words was established by the gating technique; most words could be identified before their acoustic offset. Gated words were used as congruent and incongruent sentence completions, and isolation points established in the gating experiment were compared with the time course of semantic integration evident in event-related brain potentials. Differential N400 responses to contextually appropriate and inappropriate words were observed about 200 ms before the isolation point. Semantic processing was evident before the acoustic signal was sufficient to identify the words uniquely. Results indicate that semantic integration can begin to operate with only partial, incomplete information about word identity. Influences of semantic constraint, word frequency, and rate of presentation are described.