Language switching experience is assumed to have an effect on domain-general control abilities in bilinguals, but previous studies on the relationship between these two variables have generated mixed results. The present study investigated the effects of bilingual experiences on the interaction between language switching and domain-general control. Thirty-two Dutch–French bilingual young adults executed a bilingual categorisation task to assess their language switching abilities and a Simon task to assess domain-general control. The results show that global response times on the Simon task were correlated to the forward switch cost (from L1 to L2); moreover, interestingly, the forward switch cost was found to be related to recent language exposure but not to the age of second language acquisition. We suggest a monitoring account of language switching to integrate the first finding with previous studies and we interpret the second finding as support for the adaptive control hypothesis.

The goal of the present study was to investigate the initial phases of novel grammar learning on a neural level, concentrating on mechanisms responsible for individual variability between learners. Two groups of participants, one with high and one with average language analytical abilities, performed an Artificial Grammar Learning (AGL) task consisting of learning and test phases. During the task, EEG signals from 32 cap-mounted electrodes were recorded and epochs corresponding to the learning phases were analysed. We investigated spectral power modulations over time, and functional connectivity patterns by means of a bivariate, frequency-specific index of phase synchronization termed Phase Locking Value (PLV). Behavioural data showed learning effects in both groups, with a steeper learning curve and higher ultimate attainment for the highly skilled learners. Moreover, we established that cortical connectivity patterns and profiles of spectral power modulations over time differentiated L2 learners with various levels of language analytical abilities. Over the course of the task, the learning process seemed to be driven by whole-brain functional connectivity between neuronal assemblies achieved by means of communication in the beta band frequency. On a shorter timescale , increasing proficiency on the AGL task appeared to be supported by stronger local synchronisation within the right hemisphere regions. Finally, we observed that the highly skilled learners might have exerted less mental effort, or reduced attention for the task at hand once the learning was achieved, as evidenced by the higher alpha band power.

We examine the role of language analytical ability, one of the components of language aptitude - a specific ability for learning languages - during acquisition of a novel grammar. We investigated whether the neural basis of Artificial Grammar Learning (AGL) differs between populations of highly and moderately skilled learners. Participants performed an AGL task during an fMRI scan and data from task's test phases were analysed. Highly skilled learners performed better than moderately skilled ones and engaged during the task more neural resources in the right hemisphere, i.e. in the right angular/supramarginal gyrus and superior frontal and middle frontal gyrus and in the posterior cingulate gyrus. Additional analyses investigating the temporal dynamics of brain activity during learning revealed lateralisation differences in the modulation of activity in the parietal and temporal cortex. In particular, the left angular gyrus BOLD activity was coupled with high performance on the AGL task and with a steep learning curve.

Following Opitz and Friederici (2003) suggesting interactions of the hippocampal system and the prefrontal cortex as the neural mechanism underlying novel grammar learning, the present fMRI study investigated functional connectivity of bilateral BA 44/45 and the hippocampus during an artificial grammar learning (AGL) task. Our results, contrary to the previously reported interactions, demonstrated parallel (but separate) contributions of both regions, each with their own interactions, to the process of novel grammar acquisition. The functional connectivity pattern of Broca's area pointed to the importance of coherent activity of left frontal areas around the core language processing region for successful grammar learning. Furthermore, connectivity patterns of left and right hippocampi (predominantly with occipital areas) were found to be a strong predictor of high performance on the task. Finally, increasing functional connectivity over time of both left and right BA 44/45 with the right posterior cingulate cortex and the right temporo-parietal areas points to the importance of multimodal and attentional processes supporting novel grammar acquisition. Moreover, it highlights the right-hemispheric involvement in initial stages of L2 learning. These latter interactions were found to operate irrespective of the task performance, making them an obligatory mechanism accompanying novel grammar learning.

In an effort to advance the understanding of brain function and organisation accompanying second language learning, we investigate the neural substrates of novel grammar learning in a group of healthy adults, consisting of participants with high and average language analytical abilities (LAA). By means of an Independent Components Analysis, a data-driven approach to functional connectivity of the brain, the fMRI data collected during a grammar-learning task were decomposed into maps representing separate cognitive processes. These included the default mode, task-positive, working memory, visual, cerebellar and emotional networks. We further tested for differences within the components, representing individual differences between the High and Average LAA learners. We found high analytical abilities to be coupled with stronger contributions to the task-positive network from areas adjacent to bilateral Broca's region, stronger connectivity within the working memory network and within the emotional network. Average LAA participants displayed stronger engagement within the task-positive network from areas adjacent to the right-hemisphere homologue of Broca's region and typical to lower level processing (visual word recognition), and increased connectivity within the default mode network. The significance of each of the identified networks for the grammar learning process is presented next to a discussion on the established markers of inter-individual learners' differences. We conclude that in terms of functional connectivity, the engagement of brain's networks during grammar acquisition is coupled with one's language learning abilities.

Learning to read transforms the brain, building on children's existing capacities for language and visuospatial processing. In particular, the development of print-speech convergence, or the spatial overlap of neural regions necessary for both auditory and visual language processing, is critical for literacy acquisition. Print-speech convergence is a universal signature of proficient reading, yet the antecedents of this convergence remain unknown. Here we examine the relationship between spoken language proficiency and the emergence of the printspeech network in beginning readers (ages 5-6). Results demonstrate that children's language proficiency, but not their early literacy skill, explains variance in their print-speech neural convergence in kindergarten. Furthermore, print-speech convergence in kindergarten predicts reading abilities one year later. These findings suggest that children's language ability is a core mechanism guiding the neural plasticity for learning to read, and extend theoretical perspectives on language and literacy acquisition across the lifespan.

The idea of a bilingual advantage in aspects of cognitive control—including cognitive flexibility, inhibition, working memory, and attention—is disputed. Using a sample of kindergarten children, the present study investigated associations between bilingualism and cognitive flexibility—a relationship that has shown mixed findings in prior literature. We also extend prior work by exploring relationships between bilingualism and attentional fluctuations, which represent consistency in attentional control and contribute to cognitive performance. To our knowledge, no previous study has explored this association. Theoretically, attentional fluctuations might mediate or moderate the relationship between bilingualism and cognitive flexibility. However, given evidence of null findings from extant literature when confounding variables are adequately controlled and tasks are standardized, we did not expect to find a bilingual advantage in either cognitive flexibility or attentional fluctuations. Our results supported this hypothesis when considering bilingualism both continuously and categorically. The importance of expanding upon mechanistic accounts connecting bilingualism to cognitive improvements is discussed.

Aiming at exploring the brain's structural organisation underlying successful second language learning, we investigate the anatomy of the perisylvian language network in a group of healthy adults, consisting of participants with high and average language analytical abilities. Utilising deterministic tractography, six tracts per participant (left and right long direct segment, left and right indirect anterior segment and left and right indirect posterior segment) were virtually dissected and measurements pertaining to their microstructural organisation were collected. Our results obtained by means of linear discriminant analysis pointed to mean diffusivity (MD) values of three tracts (right anterior, left long and left anterior segments) as best discriminating between the two groups. By far the highest coefficient was obtained for the MD values of the right anterior segment, pointing to the role of the right white matter fronto-parietal connectivity for superior language learning abilities. The results imply the importance of attentional processes and reasoning abilities for successful L2 acquisition, and support previous findings concerning right-hemispheric involvement in language learning.