title: Cross-language intrusion errors in aging bilinguals reveal the link between executive control and language selection.
abstract: Bilinguals outperform monolinguals on measures of executive control, but it is not known how bilingualism introduces these advantages. To address this question, we investigated whether language-control failures increase with aging-related declines in executive control. Eighteen younger and 18 older Spanish-English bilinguals completed a verbal-fluency task, in which they produced words in 18 categories (9 in each language), and a flanker task. Performance on both tasks exhibited robust effects of aging, but cross-language and within-language errors on the verbal-fluency task differed in a number of ways. Within-language errors occurred relatively often and decreased with higher levels of education in both younger and older bilinguals. In contrast, cross-language intrusions (e.g., inadvertently saying an English word on a Spanish-language trial) were rarely produced, were not associated with education level, and were strongly associated with flanker-task errors in older but not younger bilinguals. These results imply that executive control plays a role in maintaining language selection, but they also suggest the presence of independent forces that prevent language-selection errors.
authors.affiliation: Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., 0948, La Jolla, CA 92093-0948, USA. tgollan@ucsd.edu
authors.forename: Tamar H
authors.initials: TH
authors.lastname: Gollan
authors.forename: Tiffany
authors.initials: T
authors.lastname: Sandoval
authors.forename: David P
authors.initials: DP
authors.lastname: Salmon
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D056344:Executive Function; D006801:Humans; D019303:Multilingualism; D013060:Speech; D014705:Verbal Behavior; D055815:Young Adult