Neural activity during Stroop colour-word task performance in late proficient bilinguals: A functional Magnetic Resonance Imaging study.

Abstract

The aim of this study was to identify which neural substrates are engaged during manual Stroop task performance and compare the activation between 8 late profi cient Macedonian-English bilinguals and 10 matched English monolinguals. During functional magnetic resonance imaging (fMRI) adult participants performed four Stroop task conditions in a block design (control, congruent, semantically incongruent, response incongruent). Here, we focussed on differences in activation between the two groups in two contrasts: (1) the presence of task-irrelevant information that confl icts at both the response and semantic level (response incongruent versus congruent); and (2) the presence of competing task-relevant information that confl icts at the response level only (response incongruent versus semantically incongruent). For the fi rst contrast, comparisons between monolinguals (English) and the fi rst language of bilinguals (Macedonian) revealed greater activation in the posterior regions of monolinguals, possibly indicative of a more elaborate stimulus evaluation process. For the second contrast, bilinguals showed less activation in anterior cingulate and prefrontal regions than monolinguals. As poor performance on the Stroop task has been found to be associated with greater activation in these two regions, we interpret this in light of earlier ideas regarding cognitive control and the advantages of bilingualism. That is, less effortful word-form processing might indicate that bilinguals are more effectively dealing with response confl ict. Together the current fi ndings suggest that learning two languages may modify the neural substrates engaged during tasks that rely on executive functioning.

Neural correlates of cognitive processing in monolinguals and bilinguals

“…This pattern of efficiency is also observable in “late” bilinguals who acquired a second language between 9 and 17 years of age . Waldie et al . described a pattern consistent with BAPSS in English monolinguals and Macedonian–English bilinguals using a modified Stroop task.…”

“…This pattern of efficiency is also observable in “late” bilinguals who acquired a second language between 9 and 17 years of age . Waldie et al .…”

Effects of bilingualism on white matter integrity in older adults

“…The idea that bilingualism leads to structural and functional brain adaptation is increasingly supported by evidence from studies of both grey matter volume (e.g., Abutalebi et al, 2015a, 2015b; Wei et al, 2015) and functional MRI (e.g., Rodríguez-Pujadas et al, 2014; Waldie et al, 2009). However, only two studies have examined white matter integrity in older adult monolinguals and bilinguals, and these studies yielded conflicting results.…”

Language experience differentiates prefrontal and subcortical activation of the cognitive control network in novel word learning

“…Very few studies, however, have specifically examined the cognitive control mechanisms needed during the earliest stages of second language vocabulary acquisition and how experience managing multiple languages may affect the brain regions employed. Current research suggests that bilinguals have an advantage in cognitive control related tasks (Bialystok, 2001; Bialystok and Shapero, 2005; Bialystok and DePape, 2009; Carlson and Meltzoff, 2008; Kaushanskaya and Marian, 2009; Waldie et al, 2009; Ye and Zhou, 2009). Bialystok and DePape (2009) propose that bilinguals train general and language specific control abilities on a daily basis through managing multiple languages, resulting in enhanced cognitive control across many cognitive domains.…”