ISCA Workshop on Plasticity in Speech Perception (PSP2005)

Senate House, London, UK
June 15-17, 2005

Perceived Phonetic Details Are Not Necessarily Used in Lexical Acquisition

Thierry Nazzi

Universite Paris 5, Paris, France

Previous research by Nazzi and Gopnik (2001) used an object manipulation task to evaluate the ability of English-learning infants to form new object categories based on naming information alone. Results showed that naming information was used at 20 months, but not at 16 months. Given results on the lexical development of the infants tested, these results further suggest a link between the emergence of name-based categorization and changes in lexical development. After having replicated this effect in a population of Frenchlearning infants, we used this procedure to evaluate whether French-learning 20-month-olds use detailed phonetic information when simultaneously learning two new word/category pairings. We explored minimal contrasts on both consonants and vowels. Infants performed above chance level on minimal consonantal contrasts, whether the contrast was in word-initial position (e.g., /pize/ vs./tize/) or not (e.g., /pide/ vs. /pigue/). On the other hand, infants failed to learn when they were presented with words differing only by one of their vowels, independently of the position of the contrasting vowels within the word or of their acoustic distance (e.g., /pize/- /puze/, or /pize/-/paze/, or /pize/-/pizou/). This last result suggests that contrasts that have been shown to be discriminated in early infancy are not necessarily used to contrast words at the onset of lexical acquisition. Moreover, the comparison of the results for consonants and vowels suggests that these infants make different use of consonants and vowels in early lexical acquisition, a result compatible with the proposal that consonants and vowels play different roles in languages (Nespor, Pea & Mehler, 2003). Ongoing research is exploring whether this differential effect is better interpreted in terms of a consonant/vowel difference, or in terms of continuous on-continuous phonemes, by testing infants with pairs of words contrasting by continuous consonants (e.g., /lize/-/rize/).

Full Paper

Bibliographic reference.  Nazzi, Thierry (2005): "Perceived phonetic details are not necessarily used in lexical acquisition", In PSP2005, 184-187.