Learning of syllable-object relations by preverbal infants: the role of temporal synchrony and syllable distinctiveness.

The role of temporal synchrony and syllable distinctiveness in preverbal infants' learning of word-object relations was investigated. In Experiment 1, 7- and 8-month-olds (N=64) were habituated under conditions where two similar-sounding syllables, /tah/ and /gah/, were spoken simultaneously with the motions of one of two sets of objects (synchronous) or out of phase with the motions (asynchronous). On test trials, 8-month-olds, but not 7-month-olds, showed learning of the relations in the synchronous condition but not in the asynchronous condition. Furthermore, in Experiment 2, following habituation to one of the synchronous syllable-object pairs, 7-month-olds (n=8) discriminated the syllables and the objects. In Experiment 3, following habituation to two distinct syllables, /tah/-/gih/ or /gah/-/tih/, paired with identical objects, 7-month-olds (n=40) showed learning of the relations, again only in the synchronous condition. Thus, synchrony, which mothers naturally provide between words and object motions, facilitated the mapping onto objects of similar-sounding syllables at 8months of age and distinct syllables at 7months of age. These findings suggest an interaction between infants' synchrony and syllable distinctiveness perception during early word mapping development.