Conceptual relationships between spoken words and environmental sounds: event-related brain potential measures.

Identifiable nonspeech sounds were paired with spoken words. In Experiment 1, words preceded by related sounds yielded faster lexical decision times than those preceded by unrelated sounds. In Experiment 2, subjects were presented with sound/word and word/sound pairs while event-related potentials were recorded. Words preceded by related sounds elicited smaller N400 components than those preceded by unrelated sounds; this N400 context effect was slightly larger at electrode sites over the right hemisphere. A context effect similar in latency and morphology was observed for sounds-a smaller negative wave for related than unrelated sounds. The context effect for sounds was significantly larger at left than right recording sites, suggesting differential hemispheric involvement in the processing of word meanings than the "meanings" of environmental sounds.