Over the first weeks and months following birth, infants' initial, broad-based perceptual sensitivities become honed to the characteristics of their native language. In this article, we review this process of emerging specialization within the context of a cascading "critical period" (CP) framework, in which periods of maximal openness…

Visual information influences speech perception in both infants and adults. It is still unknown whether lexical representations are multisensory. To address this question, we exposed 18-month-old infants (n = 32) and adults (n = 32) to new word-object pairings: Participants either heard the acoustic form of the words or saw the talking face in…

Previous studies have suggested that the perception of vowels and consonants changes from language-universal to language-specific between 6 and 12 months of age. This report suggests that language-specific perception emerges even earlier for lexical tones. Experiment 1 tested English-learners' perception of Cantonese tones, replicating declines in…

Over their 1st year of life, infants' "universal" perception of the sounds of language narrows to encompass only those contrasts made in their native language (J. F. Werker & R. C. Tees, 1984). This research tested 40 infants in an eyetracking paradigm and showed that this pattern also holds for infants exposed to seen language--American Sign…

Can infants, in the very first stages of word learning, use their perceptual sensitivity to the phonetics of speech while learning words? Research to date suggests that infants of 14 months cannot learn two similar-sounding words unless there is substantial contextual support. The current experiment advances our understanding of this failure by…

This study investigated vowel length discrimination in infants from 2 language backgrounds, Japanese and English, in which vowel length is either phonemic or nonphonemic. Experiment 1 revealed that English 18-month-olds discriminate short and long vowels although vowel length is not phonemically contrastive in English. Experiments 2 and 3 revealed…

One of the central themes in the study of language acquisition is the gap between the linguistic knowledge that learners demonstrate, and the apparent inadequacy of linguistic input to support induction of this knowledge. One of the first linguistic abilities in the course of development to exemplify this problem is in speech perception:…

Across the first year of life, infants show decreased sensitivity to phonetic differences not used in the native language [Werker, J. F., & Tees, R. C. (1984). Cross-language speech perception: evidence for perceptual reorganization during the first year of life. "Infant Behaviour and Development," 7, 49-63]. In an artificial language learning…

Do young infants treat speech as a special signal, compared with structurally similar non-speech sounds? We presented 2- to 7-month-old infants with nonsense speech sounds and complex non-speech analogues. The non-speech analogues retain many of the spectral and temporal properties of the speech signal, including the pitch contour information…

A series of experiments indicated that by 1 year of age, infants' perceptual categories correspond to linguistically significant categories. Developmental change between 6 and 12 months shows that perceptual abilities of the 1-year-old are not arbitrary, do not reflect all the discriminatory capabilities of the infant, and are similar to phonemic…

Attempts to determine whether broadened linguistic experience facilitates cross-language phonetic sensitivity to a novel speech contrast. Multilingual adults and monolingual English speaking adults were compared on their ability to make phonetic distinctions not found in their respective native languages. Broad, nonspecific linguistic experience…