Bilingualism at the core of the brain. Structural differences between bilinguals and monolinguals revealed by subcortical shape analysis.
Naturally acquiring a language shapes the human brain through a long-lasting learning and practice process. This is supported by previous studies showing that managing more than one language from early childhood has an impact on brain structure and function. However, to what extent bilingual individuals present neuroanatomical peculiarities at the subcortical level with respect to monolinguals is yet not well understood, despite the key role of subcortical gray matter for a number of language functions, including monitoring of speech production and language control - two processes especially solicited by bilinguals. Here we addressed this issue by performing a subcortical surface-based analysis in a sample of monolinguals and simultaneous bilinguals (N=88) that only differed in their language experience from birth. This analysis allowed us to study with great anatomical precision the potential differences in morphology of key subcortical structures, namely, the caudate, accumbens, putamen, globus pallidus and thalamus. Vertexwise analyses revealed significantly expanded subcortical structures for bilinguals compared to monolinguals, localized in bilateral putamen and thalamus, as well as in the left globus pallidus and right caudate nucleus. A topographical interpretation of our results suggests that a more complex phonological system in bilinguals may lead to a greater development of a subcortical brain network involved in monitoring articulatory processes.
Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, Roc Boronat 138, 08018 Barcelona, Spain. Electronic address: miguel.burgaleta@upf.edu.
Miguel
M
Burgaleta
Department of Psychology, Jaume I University, 12071 Castellón de la Plana, Spain; Welcome Trust Centre for Neuroimaging, University College of London, WC1N 3BG, London, United Kingdom.
Ana
A
Sanjuán
Department of Psychology, Jaume I University, 12071 Castellón de la Plana, Spain; Department of Mathematics Teaching, Faculty of Teacher Training, University of Valencia, 46010 Valencia, Spain.
Noelia
N
Ventura-Campos
Center for Brain and Cognition, Department of Technology, Universitat Pompeu Fabra, Roc Boronat 138, 08018 Barcelona, Spain.
Núria
N
Sebastian-Galles
Department of Psychology, Jaume I University, 12071 Castellón de la Plana, Spain.
César
C
Ávila
D001479:Basal Ganglia / Q000033:anatomy & histology* / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D013788:Thalamus / Q000033:anatomy & histology* / Q000502:physiology*; D055815:Young Adult
Basal Ganglia; Bilingualism; Neuroanatomy; Structural MRI; Thalamus