The language recognition ability of four-month-old infants in English and Japanese spoken by a bilingual and Japanese monolingual woman

This study investigates whether four-month-old Japanese infants are able to distinguish English from Japanese spoken by a bilingual woman (level 9.5) (Experiment 1), and then, spoken by a Japanese monolingual woman (level 1) who has learned English fifty years ago and never been to English speaking countries (Experiment 2). According to Mehler et al. (1993), rhythmic cues play a role for infants when two languages are presented. The bilingual speaker has indicated English rhythmic patterns as well as Japanese, whereas the monolingual speaker has not. The experimental procedure followed Bosch & Sebastian-Galles (1997 & 2001) that have investigated four-month-old infants’ capacity to discern two rhythmically similar languages. In both researches, the scholars let infants sit between two loud speakers and recorded their reaction towards one of two speakers presenting a stimulus. Then, they have coded the infant’s Reaction Time (RT) (1997) as well as listening time (2001) to the stimuli and analyzed them. In our first experiment, ten Japanese monolingual-to-be infants were tested with English and Japanese stimuli narrated by a bilingual woman to assess the validity of the procedure. In the main experiment, mostly same infants were examined in above two languages spoken by a Japanese monolingual woman. The data from those two experiments were coded with special editing software to measure two different types of reaction, RT and listening time. The result of the first experiment indicated the validity of the procedure, i.e. that Japanese four-month-old monolingual-to-be infants distinguished English from Japanese when the bilingual woman spoke. In the second experiment, however, the infants did not discriminate those languages spoken by Japanese monolingual woman (level 1).