Neurolinguistics: Structure, Function, and Connectivity in the Bilingual Brain

Abstract

Advances in neuroimaging techniques and analytic methods have led to a proliferation of studies investigating the impact of bilingualism on the cognitive and brain systems in humans. Lately, these findings have attracted much interest and debate in the field, leading to a number of recent commentaries and reviews. Here, we contribute to the ongoing discussion by compiling and interpreting the plethora of findings that relate to the structural, functional, and connective changes in the brain that ensue from bilingualism. In doing so, we integrate theoretical models and empirical findings from linguistics, cognitive/developmental psychology, and neuroscience to examine the following issues: (1) whether the language neural network is different for first (dominant) versus second (nondominant) language processing; (2) the effects of bilinguals' executive functioning on the structure and function of the “universal” language neural network; (3) the differential effects of bilingualism on phonological, lexical-semantic, and syntactic aspects of language processing on the brain; and (4) the effects of age of acquisition and proficiency of the user's second language in the bilingual brain, and how these have implications for future research in neurolinguistics.

What Influences Language Impairment in Bilingual Aphasia? A Meta-Analytic Review

“…There has been discussion in the literature regarding the degree to which language similarity influences the comparability of impairment in bilingual aphasia (Lorenzen and Murray, 2008). Whereas, on the one hand, one might predict that more similar languages would look similarly impaired following a stroke, there is little evidence to support this prediction and there is controversy in the literature regarding the role of language similarity on the neuronal organization of the languages of a bilingual (Kumar, 2014; Wong et al, 2016). On the other hand, one could assume that because linguistically similar languages share a significant portion of lexico-semantic representation (e.g., cognates), more cognitive control may be required to overcome cross-language interference.…”

ERP Response Unveils Effect of Second Language Manipulation on First Language Processing

“…A less pronounced priming effect for homograph-unrelated group in the central electrodes can be due to an increased inhibition for those electrodes. Indeed, as the fronto-parietal network (for review see [62]) is considered responsible for cognitive control and also involved in second language processing [62], we assert that the observed inhibition in these electrodes is due to the top-down cognitive control.…”

Enhancement of posterior brain functional networks in bilingual older adults

“…The regions included in the analyses were the caudate, the putamen, the globus pallidus and the anterior cingulate cortex. This subset of regions has been found to be specifically modulated by bilingualism in previous works (Grundy et al, 2017;Wong et al, 2016). Correlations were calculated for each group separately to independently observe the relationship between variables in each population.…”