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.
Kuhl
Patricia K
PK
Institute for Learning and Brain Sciences and Department of Speech and Hearing Sciences, University of Washington 98195, USA. pkkuhl@u.washington.edu
Stevens
Erica
E
Hayashi
Akiko
A
Deguchi
Toshisada
T
Kiritani
Shigeru
S
Iverson
Paul
P
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