Recently it has been proposed that sensitivity to nonarbitrary relationships between speech sounds and objects potentially bootstraps lexical acquisition. However, it is currently unclear whether preverbal infants (e.g., before 6 months of age) with different linguistic profiles are sensitive to such nonarbitrary relationships. Here, the authors…

The development of the ability to categorize speech sounds is often viewed as occurring primarily during infancy via perceptual learning mechanisms. However, a number of studies suggest that even after infancy, children's categories become more categorical and well defined through about age 12. We investigated the cognitive changes that may be…

It was concluded that both social and vocal elements are necessary to stimulate a general increase in the number and length of consonant utterances, but there was no evidence that stimulation encouraged infants to imitate the consonant phonemes presented. (Author)