Bilingualism influences structural indices of interhemispheric organization

Abstract

Bilingualism represents an interesting model of possible experience-dependent alterations in brain structure. The current study examines whether interhemispheric adaptations in brain structure are associated with bilingualism. Corpus callosum volume and cortical thickness asymmetry across 13 regions of interest (selected to include critical language and bilingual cognitive control areas) were measured in a sample of Spanish-English bilinguals and age- and gender-matched monolingual individuals (N = 39 per group). Cortical thickness asymmetry of the anterior cingulate region differed across groups, with thicker right than left cortex for bilinguals and the reverse for monolinguals. In addition, two adjacent regions of the corpus callosum (mid-anterior and central) had greater volume in bilinguals. The findings suggest that structural indices of interhemispheric organization in a critical cognitive control region are sensitive to variations in language experience.

Does bilingualism increase brain or cognitive reserve in patients with temporal lobe epilepsy?

“…Contrary to our first hypothesis, we found reductions in FA and increases in MD of fiber tracts implicated in EF in bilingual patients with TLE relative to the HC groups and monolingual patients with TLE. Greater WM integrity has been reported in bilingual healthy adults, children, and older adults; this could represent greater available neural substrates. The changes in WM structure in bilingual subjects have been proposed to lead to more widely distributed cognitive networks, resulting in more efficient communication between brain regions.…”

Neural correlates of cognitive processing in monolinguals and bilinguals

“…Felton et al . found similar results in young adults . They examined the corpus callosum and found that bilinguals had greater volume in the middle‐anterior and central regions than monolinguals.…”

Effects of bilingualism on white matter integrity in older adults

“…Structural magnetic resonance imaging (MRI) has revealed that young adult bilinguals have greater white matter volume than their monolingual peers. These differences are particularly reliable in the corpus callosum, and may allow bilinguals to exchange cross-hemispheric information more efficiently than monolinguals (e.g., Coggins et al, 2004; Felton et al, 2017). …”