title: Age of second language acquisition affects nonverbal conflict processing in children: an fMRI study.
abstract: BACKGROUND
  In their daily communication, bilinguals switch between two languages, a process that involves the selection of a target language and minimization of interference from a nontarget language. Previous studies have uncovered the neural structure in bilinguals and the activation patterns associated with performing verbal conflict tasks. One question that remains, however is whether this extra verbal switching affects brain function during nonverbal conflict tasks.
  
  
  METHODS
  In this study, we have used fMRI to investigate the impact of bilingualism in children performing two nonverbal tasks involving stimulus-stimulus and stimulus-response conflicts. Three groups of 8-11-year-old children--bilinguals from birth (2L1), second language learners (L2L), and a control group of monolinguals (1L1)--were scanned while performing a color Simon and a numerical Stroop task. Reaction times and accuracy were logged.
  
  
  RESULTS
  Compared to monolingual controls, bilingual children showed higher behavioral congruency effect of these tasks, which is matched by the recruitment of brain regions that are generally used in general cognitive control, language processing or to solve language conflict situations in bilinguals (caudate nucleus, posterior cingulate gyrus, STG, precuneus). Further, the activation of these areas was found to be higher in 2L1 compared to L2L.
  
  
  CONCLUSIONS
  The coupling of longer reaction times to the recruitment of extra language-related brain areas supports the hypothesis that when dealing with language conflicts the specialization of bilinguals hampers the way they can process with nonverbal conflicts, at least at early stages in life.
authors.affiliation: Medical Imaging Department (BEFY), Vrije Universiteit Brussel (VUB) Brussels, Belgium ; Radiology Department, UZ Brussel Brussels, Belgium.
authors.forename: Seyede Ghazal
authors.initials: SG
authors.lastname: Mohades
authors.affiliation: Department of Linguistics, Vrije Universiteit Brussel Brussels, Belgium.
authors.forename: Esli
authors.initials: E
authors.lastname: Struys
authors.affiliation: Radiology Department, UZ Brussel Brussels, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Van Schuerbeek
authors.affiliation: Department of Psychiatry, UZ Brussel Brussels, Belgium ; Department of Psychiatry and Medical Psychology, Ghent University Ghent, Belgium.
authors.forename: Chris
authors.initials: C
authors.lastname: Baeken
authors.affiliation: Department of Linguistics, Vrije Universiteit Brussel Brussels, Belgium.
authors.forename: Piet
authors.initials: P
authors.lastname: Van De Craen
authors.affiliation: Medical Imaging Department (BEFY), Vrije Universiteit Brussel (VUB) Brussels, Belgium ; Radiology Department, UZ Brussel Brussels, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Luypaert
mesh_terms: D000367:Age Factors; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D002648:Child; D005260:Female; D006801:Humans; D007804:Language Development; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D019303:Multilingualism; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology
keywords: Bilingualism; Simon; Stroop; children; conflict; congruency effect; fMRI