Accessing spoken words: The importance of word onsets.

Approaches to spoken word recognition differ in the importance they assign to word onsets during lexical access. This research contrasted the hypothesis that lexical access is strongly directional with the hypothesis that word onsets are less important than the overall goodness of fit between input and lexical form. A cross-modal priming technique was used to investigate the extent to which a rhyme prime (a prime that differs only in its first segment from the word that is semantically associated with the visual probe) is as effective a prime as the original word itself. Earlier research had shown that partial primes that matched from word onset were very effective cross-modal primes. The present results show that, irrespective of whether the rhyme prime was a real word or not, and irrespective of the amount of overlap between the rhyme prime and the original word, the rhymes are much less effective primes than the full word. In fact, no overall priming effect could be detected at all except under conditions in which the competitor environment was very sparse. This suggests that word onsets do have a special status in the lexical access of spoken words. A fundamental property of the speech signal is its intrinsic directionality in time. Spoken utterances are spread out along the time line, moving necessarily from beginning to end, in a way that is not true of written language. This directionality of the speech input is strongly reflected in the claims made by the cohort model of spoken word recognition for the manner in which speech inputs are mapped onto the representations of word forms in the mental lexicon (Marslen-Wilson, 1984, 1987; Marslen-Wilson Marslen-Wilson Tyler, 1984; Tyler Warren & Marslen-Wilson, 1987). The cohort model of word recognition stresses the sequential and continuous nature of the mapping between the speech input and mental representations of word forms. This emphasis is closely tied up with the concept of a cohort and its implications for the properties of the on-line lexical decision space. In particular, according to the cohort model, the decision space is determined by the beginnings of words. The speech input at the beginning of the word maps onto all lexical items that share the same initial sequence. This initial set of candidates is termed the word-initial cohort, and the subsequent process of word recognition is determined by the