title: Language and task switching in the bilingual brain: Bilinguals are staying, not switching, experts.
abstract: Bilinguals' ability to control which language they speak and to switch between languages may rely on neurocognitive mechanisms shared with non-linguistic task switching. However, recent studies also reveal some limitations on the extent control mechanisms are shared across domains, introducing the possibility that some control mechanisms are unique to language. We investigated this hypothesis by directly comparing the neural correlates of task switching and language switching. Nineteen Spanish-English bilingual university students underwent a functional magnetic resonance imaging (fMRI) study employing a hybrid (event-related and blocked) design involving both color-shape switching and language switching paradigms. We compared the two switching tasks using within-subject voxel-wise t-tests for each of three trial types (single trials in single blocks, and stay and switch trials in mixed blocks). Comparing trial types to baseline in each task revealed widespread activation for single, stay, and switch trials in both color-shape and language switching. Direct comparisons of each task for each trial type revealed few differences between tasks on single and switch trials, but large task differences during stay trials, with more widespread activation for the non-linguistic than for the language task. Our results confirm previous suggestions of shared mechanisms of switching across domains, but also reveal bilinguals have greater efficiency for sustaining the inhibition of the non-target language than the non-target task when two responses are available. This efficiency of language control might arise from bilinguals' need to control interference from the non-target language specifically when not switching languages, when speaking in single- or mixed-language contexts.
authors.affiliation: San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct. #103, San Diego 92120-4913, United States.
authors.forename: Gali H
authors.initials: GH
authors.lastname: Weissberger
authors.affiliation: Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., MC: 0603, La Jolla, CA 92093-0603, United States.
authors.forename: Tamar H
authors.initials: TH
authors.lastname: Gollan
authors.affiliation: VA San Diego Healthcare System, 3350 La Jolla Village Dr., San Diego 92161, United States; Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., MC: 0603, La Jolla, CA 92093-0603, United States.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Bondi
authors.affiliation: San Diego State University/University of California, San Diego, Joint Doctoral Program in Clinical Psychology, 6363 Alvarado Ct. #103, San Diego 92120-4913, United States.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Clark
authors.affiliation: VA San Diego Healthcare System, 3350 La Jolla Village Dr., San Diego 92161, United States; Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., MC: 0603, La Jolla, CA 92093-0603, United States. Electronic address: cwierenga@ucsd.edu.
authors.forename: Christina E
authors.initials: CE
authors.lastname: Wierenga
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D055815:Young Adult
keywords: Bilingualism; Executive control; Linguistic control; Task switching; fMRI