title: Language proficiency modulates the engagement of cognitive control areas in multilinguals.
abstract: Language proficiency should modulate the regions involved in language control in predictable ways during language switching. However, prior studies reveal inconsistent effects on the regions involved in language monitoring [pre-Supplementary Motor Area/Anterior Cingulate Cortex (pre-SMA/ACC)] and language selection (left caudate) conceivably because variations in relative proficiency are confounded with other between-group differences. We circumvented this problem in an fMRI (functional Magnetic Resonance Imaging) study of overt picture naming in trilingual participants. In this case, the difference between a high-proficient and a low-proficient further language can be assessed within subjects with no between-group confound. We also used a monolingual group to assess the neural correlates of switching between two categories of response within the same language. We report a novel result: relative language proficiency dissociates response of the pre-SMA/ACC and left caudate during language switching. Switching between languages increased pre-SMA/ACC response regardless of proficiency differences. By contrast, left caudate response did vary with proficiency differences. Switching from the most to the least proficient language increased the response. Within-language switching, as contrasted with between-language switching, elicited a comparable increase in pre-SMA/ACC response but a decrease in left caudate response. Taken together, our data support a wider role of pre-SMA/ACC in task monitoring and establish the critical role of the left caudate in the selection of the less proficient language in language switching.
authors.affiliation: Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Jubin
authors.initials: J
authors.lastname: Abutalebi
authors.forename: Pasquale A
authors.initials: PA
authors.lastname: Della Rosa
authors.forename: Guosheng
authors.initials: G
authors.lastname: Ding
authors.forename: Brendan
authors.initials: B
authors.lastname: Weekes
authors.forename: Albert
authors.initials: A
authors.lastname: Costa
authors.forename: David W
authors.initials: DW
authors.lastname: Green
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D011597:Psychomotor Performance / Q000502:physiology