Biology subjects

Marca, S. C.

Publications and source records attributed to Marca, S. C..

2 recordsLinked to original sources

bioRxiv2025

Proficiency-Dependent and Dynamic Reorganization of Brain Networks During Children's Second Language Learning

Childrens second language (L2) vocabulary learning is often indexed with event-related potentials (ERPs) by the N400 incongruity effect, yet its stability in real classrooms is unclear. We recorded 64-channel EEG from 42 children (aged 9-15 years) during a translation-recognition task before and after a regular instructional vocabulary unit and sub-grouped children by baseline proficiency. We quantified the canonical N400 (300-500 ms, centroparietal region of interest; ROI) alongside electrical-neuroimaging indices of ERP strength and topography (Global Field Power, Global Map Dissimilarity, ERP template-map preponderance), using adult template maps from a prior study as a normative reference. Behaviorally, children showed large gains in vocabulary accuracy and higher discrimination sensitivity (d') in post-assessment. The classical N400 incongruity effect did not increase from pre- to post-learning. By contrast, global and topographic measures were learning-sensitive: Global Field Power increased across sessions and interacted with proficiency, and Global Map Dissimilarity showed main effects of session and proficiency as well as their interaction, indicating proficiency-dependent topographic reorganization. Adult normative template maps backfitted well; within the N400 window, high-proficiency children more consistently occupied an adult-like configuration; later ([~]650-800 ms), patterns also differentiated by proficiency and congruency. Relative to adults, children exhibited more diffuse topographies and stronger dependence on individual proficiency. In classroom settings, childrens L2 vocabulary learning is therefore more sensitively indexed by scalp topography and global field dynamics than by a single N400 amplitude, positioning electrical neuroimaging as a proficiency-dependent, classroom-relevant marker of L2 acquisition.

neuroscience↗

bioRxiv2025

Brain Network Differences in Second Language Learning Depend on Individual Competencies

Integrating new words into an existing semantic network is a core challenge of second language (L2) acquisition. We investigated how evidence-based learning strategies and individual performance shape the neurocognitive dynamics of vocabulary learning. Eighty- three adults with German or French as their native language (L1) learned 48 Finnish (L2) nouns over 14 days using a mobile app that systematically varied retrieval practice, corrective feedback, multisensory learning, and distributed learning. Before and after training, EEG was recorded during a translation recognition task designed to elicit the N400, an index of semantic integration. Vocabulary accuracy increased from 0.41% pre-learning to 75.5% post- learning (dz = 3.96), and the N400 incongruity effect increased significantly, F(1, 75) = 99.52, p < .001, {superscript 2}g = .32, reflecting successful integration of new L2 words into the mental lexicon. High performers showed larger N400 responses and distinct ERP template-map preponderance (i.e., the proportion of epoch time points assigned to a given template map) indicating more efficient and specialized neural processing. Despite systematic manipulation of learning strategies, no single approach yielded consistent behavioral or neural advantages, suggesting that overall exposure and cumulative practice--rather than any specific strategy-- were the key drivers of robust learning. ERP template-map analyses further revealed that learning not only amplified neural responses but also shifted the preponderance of maps in the N400 window, signaling a qualitative reorganization of semantic processing. These findings bridge cognitive neuroscience and language education, suggesting that the depth and success of vocabulary learning may depend more on the degree of integration achieved than on the specific instructional strategy employed.

neuroscience↗