LANGUAGE DOMINANCE IN BILINGUALS ARITHMETIC OPERATIONS ACCORDING TO THEIR LANGUAGE USE

This study investigated the alleged persistence of first language dominance for arithmetic operations in bilinguals. Thirty two Japanese-English bilinguals aged 19-58 years solved arithmetic problems presented auditorily. They were required to respond verbally in the language in which the problems were presented. The problems were presented only in one language in each experimental session so that the participants did not have to switch between two languages. The participants were divided into short-term and long-term residents according to their length of residence in the U.S. and self-estimated percentage of English use per day. Reaction time data from the two groups were then analyzed. For the short-term residents, a strong dominance for calculation in Japanese was found, but this dominance decreased with increasing length of residence in the U.S. and their extent of English use. For the long-term residents, reaction times in English and Japanese were virtually identical. Possible explanations for first language dominance are discussed.