Jennifer A. Johnson
Lawrence D. Rosenblum
Dept. of Psychol., Univ. of California, Riverside, Riverside, CA 92521
Mark A. Schmuckler
Univ. of Toronto, Scarborough Campus, Toronto, Canada
In the McGurk effect, auditory speech syllables are influenced by simultaneous presentation of discrepant visible speech syllables [McGurk and McDonald, Nature 264, 746--748 (1976)]. The effect is known to be stronger for native English than native Japanese-speaking subjects [Sekiyama and Tokhura, J. Acoust. Soc. Am. 90 (1991)]. It is unknown whether the strength of the effect is something lost or gained through developmental exposure to a given language. To explore this issue, two experiments tested for the McGurk effect in 5-month-old English-exposed infants. Infants were first gaze-habituated to an audiovisual /va/. They were then presented three different audiovisual combinations: audio /va/--visual /va/; audio /ba/--visual /va/ (perceived by adults as /va/); and audio /da/--visual /va/ (perceived by adults as /da/). The infants habituated to the tokens with audio /ba/ and /va/ components at the same rate, but habituated more slowly to the token with audio /da/. Further tests with a neutral static face and changing auditory syllables revealed that these habituation differences were not due to the auditory similarity of /ba/ to /va/ relative to /da/. This suggests that the infants were visually influenced in the same way as English-speaking adults.