Neurophysiological evidence of rapid holistic tone-based lexical access

Word accents are restricted by a word's morphological structure but also distinguish lexical meanings in minimal pairs. We investigated how early tonal information carried by morphophonemic word accents influences rapid lexical access in native speakers. We also asked whether tone-bearing words are decomposed into morphemes and word accents, or retrieved holistically via full-form neural representations. Here, suffix morpheme and word accent tone were varied orthogonally to create valid and invalid combinations of tone and morphological structure/segmental information. These stimuli were presented in a passive oddball paradigm during an electroencephalography experiment, and mismatch negativity (MMN) responses were obtained. Valid combinations elicited an early-onset lexical MMN, with main sources in the left middle posterior temporal lobe-an area implicated in lexical memory. Words with morphophonemic tones appear to have full-form lexical memory traces that join segmental and tonal information. As incorrect word accent tones impeded automatic lexical retrieval, we also conclude that word accents may function in a manner similar to lexical tones in distinguishing lexical meanings.