Anatomical connectivity changes in the bilingual brain

Neuroimage. 2014 Jan 1;84:495-504. doi: 10.1016/j.neuroimage.2013.08.064. Epub 2013 Sep 7.

Abstract

How the brain deals with more than one language and whether we need different or extra brain language sub-networks to support more than one language remain unanswered questions. Here, we investigate structural brain network differences between early bilinguals and monolinguals. Using diffusion-weighted MRI (DW-MRI) tractography techniques and a network-based statistic (NBS) procedure, we found two structural sub-networks more connected by white matter (WM) tracts in bilinguals than in monolinguals; confirming WM brain plasticity in bilinguals. One of these sub-networks comprises left frontal and parietal/temporal regions, while the other comprises left occipital and parietal/temporal regions and also the right superior frontal gyrus. Most of these regions have been related to language processing and monitoring; suggesting that bilinguals develop specialized language sub-networks to deal with the two languages. Additionally, a complex network analysis showed that these sub-networks are more graph-efficient in bilinguals than monolinguals and this increase seems to be at the expense of a whole-network graph-efficiency decrease.

Keywords: Bilingualism; Efficiency; Language; Network; Tractography.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / anatomy & histology*
  • Brain / physiology*
  • Connectome / methods*
  • Diffusion Tensor Imaging / methods
  • Female
  • Humans
  • Male
  • Multilingualism*
  • Nerve Net / anatomy & histology*
  • Nerve Net / physiology*
  • Neuronal Plasticity / physiology*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spain
  • Young Adult