Word Segmentation by 8-Month-Olds: When Speech Cues Count More Than Statistics

Abstract

Fluent speech contains few pauses between adjacent words. Cues such as stress, phonotactic constraints, and the statistical structure of the input aid infants in discovering word boundaries. None of the many available segmentation cues is foolproof. So, we used the headturn preference procedure to investigate infants' integration of multiple cues. We also explored whether infants find speech cues produced by coarticulation useful in word segmentation. Using natural speech syllables, we replicated Saffran, Aslin, et al.'s (1996) study demonstrating that 8-month-olds can segment a continuous stream of speech based on statistical cues alone. Next, we added conflicting segmentation cues. Experiment 2 pitted stress against statistics, whereas Experiment 3 pitted coarticulation against statistics. In both cases, 8-month-olds weighed speech cues more heavily than statistical cues. This observation was verified in Experiment 4, which indicated that greater complexity of the familiarization sequence does not necessarily lead to familiarity effects.