Language switching costs in bilingual mathematics learning: Transfer effects and individual differences

Abstract

There is an implicit assumption in Content- and Language Integrated Learning that the acquired knowledge is represented independently of the language of instruction. However, it could be shown in several experimental intervention studies that cognitive costs (i. e. longer reaction times and lower accuracy) arise when the languages of study and retrieval do not match. In the present study, we focused on arithmetic fact learning and investigated whether these cognitive costs generalize to more complex contexts. In addition, we explored the relationship between the cognitive costs and individual differences in executive functions, intelligence, mathematical competence and second language (L2) proficiency. Participants were 58 German-French bilingual university students (L2 proficiency B2 or above). They studied multiplication facts for 3 consecutive days in either their L1 or L2, followed by a test in both languages on the 4th day. Cognitive costs caused by language switching between training and test were found for both problems requiring simple fact retrieval and problems requiring knowledge application in novel, more complex text problems. The costs were negatively related with L2 proficiency and positively with inhibition. This study shows for the first time that language switching costs can be found in situations when knowledge needs to be applied in a new context, as it is often necessary in classroom learning. Implications of this study will be discussed with regards to bilingual arithmetic learning.