The role of the left inferior parietal lobule in second language learning: An intensive language training fMRI study

Abstract

Research to date suggests that second language acquisition results in functional and structural changes in the bilingual brain, however, in what way and how quickly these changes occur remains unclear. To address these questions, we studied fourteen English-speaking monolingual adults enrolled in a 12-week intensive French language-training program in Montreal. Using functional MRI, we investigated the neural changes associated with new language acquisition. The participants were scanned before the start of the immersion program and at the end of the 12 weeks. The fMRI scan aimed to investigate the brain regions recruited in a sentence reading task both in English, their first language (L1), and in French, their second language (L2). For the L1, fMRI patterns did not change from Time 1 to Time 2, while for the L2, the brain response changed between Time 1 and Time 2 in language-related areas. Of note, for the L2, there was higher activation at Time 2 compared to Time 1 in the left inferior parietal lobule (IPL) including the supramarginal gyrus. At Time 2 this higher activation in the IPL correlated with faster L2 reading speed. Moreover, higher activation in the left IPL at Time 1 predicted improvement in L2 reading speed from Time 1 to Time 2. Our results suggest that learning-induced plasticity occurred as early as 12 weeks into immersive second-language training, and that the IPL appears to play a special role in language learning.

Dorsolateral Prefrontal Transcranial Direct Current Stimulation Modulates Language Processing but Does Not Facilitate Overt Second Language Word Production

“…This was reflected in increased activity in the left IPL (BA 40) after anodal relative to sham stimulation in L2. This is in line with a recent study highlighting the importance of this area in L2 acquisition and performance ( Barbeau et al, 2017 ). In a 12-week intensive language training, activity in this area prior to training predicted success of the training, and activity in area after training correlated with L2 performance.…”

Connectivity of the hippocampus and Broca's area during acquisition of a novel grammar

“…The regions in and surrounding the right TPJ are particularly important for multimodal processing. The importance of the inferior parietal lobule for language learning has been previously established by our group (Kepinska et al, 2017b), as well as by others (Barbeau et al, 2016;Goranskaya et al, 2016;Prat et al, 2016). The TPJ itself has been associated with reorienting of attention, theory of mind (Krall et al, 2015) and in more general terms, with updating internal models of the environment (Geng and Vossel, 2013).…”

Bilingual experience and resting-state brain connectivity: Impacts of L2 age of acquisition and social diversity of language use on control networks

“…AoA, and social diversity of language use (i.e., language entropy), focusing on five brain areas implicated in bilingual language control by the NLC model: (1 and 2) BAs 44 and 47 in the LIFG (Luk et al, 2012); (3) ACC (Abutalebi et al, 2012); (4) left caudate (Luk et al, 2012); and (5) left IPL (Barbeau et al, 2016).…”