Infants show a facilitation effect for native language phonetic perception between 6 and 12 months.
Patterns of developmental change in phonetic perception are critical to theory development. Many previous studies document a decline in nonnative phonetic perception between 6 and 12 months of age. However, much less experimental attention has been paid to developmental change in native-language phonetic perception over the same time period. We hypothesized that language experience in the first year facilitates native-language phonetic performance between 6 and 12 months of age. We tested 6-8- and 10-12-month-old infants in the United States and Japan to examine native and nonnative patterns of developmental change using the American English /r-l/ contrast. The goals of the experiment were to: (a) determine whether facilitation characterizes native-language phonetic change between 6 and 12 months of age, (b) examine the decline previously observed for nonnative contrasts and (c) test directional asymmetries for consonants. The results show a significant increase in performance for the native-language contrast in the first year, a decline in nonnative perception over the same time period, and indicate directional asymmetries that are constant across age and culture. We argue that neural commitment to native-language phonetic properties explains the pattern of developmental change in the first year.
Institute for Learning and Brain Sciences and Department of Speech and Hearing Sciences, University of Washington 98195, USA. pkkuhl@u.washington.edu
Patricia K
PK
Kuhl
Erica
E
Stevens
Akiko
A
Hayashi
Toshisada
T
Deguchi
Shigeru
S
Kiritani
Paul
P
Iverson
D000367:Age Factors; D003466:Cultural Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D007564:Japan; D007804:Language Development; D008297:Male; D010700:Phonetics; D013067:Speech Perception; D014481:United States