Brain signatures of early lexical and morphological learning of a new language

Do French speakers have an advantage in learning English vocabulary thanks to familiar suffixes?

Previous research has shown that languages from nearby families are easier to learn as second languages (L2) than languages from more distant families, attributing this difference to the presence of shared elements between the native language (L1) and L2. Building on this idea, we hypothesised that suffixes present in L1 might facilitate complex word acquisition in L2. To test this hypothesis, we recruited 76 late French-English bilinguals and tasked them with learning a set of 80 English-derived words containing suffixes that also exist in French (e.g., -able) or are unique to English (e.g., -ness). Consolidation of the learned words was assessed 1 week after the last learning session. The results showed a significant learning effect across the learning trials and consolidation, suggesting that the bilingual participants were able to acquire the derived words. However, contrary to our hypothesis, suffixes also existing in French did not give a significant advantage over English-unique suffixes. Further analysis revealed that this was due to variations in the consistency of familiar suffixes from L1. While some translation pairs shared the same suffix (e.g., amazement-étonnement), others had different suffixes (e.g., slippage-glissement). The type of translation pair with inconsistent suffix overlap (slippage-glissement) carried learning costs, preventing the bilingual participants from benefitting from the presence of familiar suffixes in L2 words. These findings suggest that shared information can be used effectively for L2 learning only if the mapping between L1 and L2 is consistent.

Investigation into white matter microstructure differences in visual training by using an automated fiber tract subclassification segmentation quantification method

Visual training has emerged as a useful framework for investigating training-related brain plasticity, a highly complex task involving the interaction of visual orientation, attention, reasoning, and cognitive functions. However, the effects of long-term visual training on microstructural changes within white matter (WM) is poorly understood. Therefore, a set of visual training programs was designed, and automated fiber tract subclassification segmentation quantification based on diffusion magnetic resonance imaging was performed to obtain the anatomical changes in the brains of visual trainees. First, 40 healthy matched participants were randomly assigned to the training group or the control group. The training group underwent 10 consecutive weeks of visual training. Then, the fiber tracts of the subjects were automatically identified and further classified into fiber clusters to determine the differences between the two groups on a detailed scale. Next, each fiber cluster was divided into segments that can analyze specific areas of a fiber cluster. Lastly, the diffusion metrics of the two groups were comparatively analyzed to delineate the effects of visual training on WM microstructure. Our results showed that there were significant differences in the fiber clusters of the cingulate bundle, thalamus frontal, uncinate fasciculus, and corpus callosum between the training group compared and the control group. In addition, the training group exhibited lower mean fractional anisotropy, higher mean diffusivity and radial diffusivity than the control group. Therefore, the long-term cognitive activities, such as visual training, may systematically influence the WM properties of cognition, attention, memory, and processing speed.

Testing the influence of musical expertise on novel word learning across the lifespan using a cross-sectional approach in children, young adults and older adults

Word learning is a multifaceted perceptual and cognitive task that is omnipresent in everyday life. Currently, it is unclear whether this ability is influenced by age, musical expertise or both variables. Accordingly, we used EEG and compared behavioral and electrophysiological indices of word learning between older adults with and without musical expertise (older adults' perspective) as well as between musically trained and untrained children, young adults, and older adults (lifespan perspective). Results of the older adults' perspective showed that the ability to learn new words is preserved in elderly, however, without a beneficial influence of musical expertise. Otherwise, results of the lifespan perspective revealed lower error rates and faster reaction times in young adults compared to children and older adults. Furthermore, musically trained children and young adults outperformed participants without musical expertise, and this advantage was accompanied by EEG manifestations reflecting faster learning and neural facilitation in accessing lexical-semantic representations.

Tracking the microstructural properties of the main white matter pathways underlying speech processing in simultaneous interpreters

Due to the high linguistic and cognitive demands placed on real-time language translation, professional simultaneous interpreters (SIs) have previously been proposed to serve as a reasonable model for evaluating experience-dependent brain properties. However, currently it is still unknown whether intensive language training during adulthood might be reflected in microstructural changes in language-related white matter pathways contributing to sound-to-meaning mapping, auditory-motor integration, and verbal memory functions. Accordingly, we used a fully automated probabilistic tractography algorithm and compared the white matter microstructure of the bilateral inferior longitudinal fasciculus (ILF), uncinate fasciculus (UF), and arcuate fasciculus (AF, long and anterior segments) between professional SIs and multilingual control participants. In addition, we classically re-evaluated the three constitutional elements of the AF (long, anterior, and posterior segments) using a deterministic manual dissection procedure. Automated probabilistic tractography demonstrated overall reduced mean fractional anisotropy (FA) and increased radial diffusivity (RD) in SIs in the fiber tracts of the left hemisphere (LH). Furthermore, SIs exhibited reduced mean FA in the bilateral AF. However, according to manual dissection, this effect was limited to the anterior AF segment and accompanied by increased mean RD. Deterministic AF reconstruction also uncovered increased mean FA in the right and RD in the left long AF segment in SIs compared to controls. These results point to a relationship between simultaneous interpreting and white matter organization of pathways underlying speech and language processing in the language-dominant LH as well as of the AF.

Statistical and Cooperative Learning in Reading: An Artificial Orthography Learning Study

This paper reports two experiments in which the artificial orthography paradigm was used to investigate the mechanisms underlying learning to read. In each experiment, participants were taught the meanings and pronunications of words written in an unfamiliar orthography and the statistical structure of the mapping between written and spoken forms (O-P) was manipulated independently of the mapping between written forms and their meanings (O-S). Our results support three main conclusions. First, the statistical structure of O-P and O-S mappings determined how easily each of those mappings was learned, suggesting that the learning of both mappings engages a common statistical learning mechnism. Second, learning to read is a cooperative process, in that learning in any particular component of the reading system is influenced by knowledge stored in the rest of the system. Finally, knowledge of sublexical regularities can be acquired as the result of exposure to words embodying those regularities.

Neural Correlates of Morphology Acquisition through a Statistical Learning Paradigm

The neural basis of statistical learning as it occurs over time was explored with stimuli drawn from a natural language (Russian nouns). The input reflected the "rules" for marking categories of gendered nouns, without making participants explicitly aware of the nature of what they were to learn. Participants were scanned while listening to a series of gender-marked nouns during four sequential scans, and were tested for their learning immediately after each scan. Although participants were not told the nature of the learning task, they exhibited learning after their initial exposure to the stimuli. Independent component analysis of the brain data revealed five task-related sub-networks. Unlike prior statistical learning studies of word segmentation, this morphological learning task robustly activated the inferior frontal gyrus during the learning period. This region was represented in multiple independent components, suggesting it functions as a network hub for this type of learning. Moreover, the results suggest that subnetworks activated by statistical learning are driven by the nature of the input, rather than reflecting a general statistical learning system.