Non temporal determinants of bilingual memory capacity: The role of long-term representations and fluency

Abstract

Two experiments examine the view that the variation in bilingual short-term memory capacity is determined by differential rates of subvocal rehearsal between the languages. Auditory memory span and articulation time were measured for three bilingual groups who spoke Finnish at home and Swedish at school (FS), and either Finnish (FF) or Swedish (SS) in both the home and the school. The results of Experiment 1 indicate that memory span for words varied in a lawful manner as a function of both articulation time and language dominance for SS and FF. For FS, however, an equivalent memory span between the languages was noted despite a shorter articulation time in Finnish than Swedish. Experiment 2 found that for items with no pre-existing lexical representations (nonwords), articulation time was a more reliable predictor of memory span than language dominance for all three groups. The finding that within-language memory span was greater for short items than long items shows that, ceteris paribus, bilingual short-term memory capacity is sensitive to the effects of word length in both the dominant and non-dominant language. Taken together, these findings moderate the view that bilingual short-term memory capacity is mediated exclusively by subvocal rehearsal and indicate an influential contribution from factors related to language fluency and the strength of lexico-semantic representations.