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Neural Efficiency in Adult Word Learning: Evidence for overlap across language, cognitive control, and flexibility networks
Poster Session C, Saturday, September 13, 11:00 am - 12:30 pm, Field House
Julie Schneider1,2, Tengwen Fan2; 1University of California Los Angeles, 2Louisiana State University
The ability to derive the meaning of a novel word from linguistic context is crucial for vocabulary growth and draws on several cognitive faculties, including retrieving the meanings of known words (semantics), integrating sentence structure (syntax), maintaining potential meanings (cognitive control), and continuously revising interpretations as new information emerges (cognitive flexibility). Accordingly, novel word learning likely recruits a broad network of brain regions associated with language processing, cognitive control, and cognitive flexibility; however, the extent to which these systems overlap remains poorly understood. Overlapping neural activation may reflect neural efficiency, whereby the brain repurposes existing circuits to support rapid vocabulary acquisition. While prior work has characterized visual word learning networks (e.g., Mestres-Missé et al., 2008), little is known about auditory word learning—the primary modality through which adults typically acquire new words. The present study addresses this gap by examining the neural basis of auditory word learning in adults and its overlap with language, cognitive control, and cognitive flexibility networks. Eighteen young adults (Mage = 19.40, SDage = 1.64) completed an auditory word learning task (Momsen et al., 2022), an auditory language localizer (Scott et al., 2016), a domain-general executive control task (Duncan, 2010, 2013; Fedorenko et al., 2013), and a cognitive flexibility task (Engelhardt et al., 2019; Nugiel et al., 2020, 2023) during fMRI scanning. All participants scored within the normal range on the NIH Toolbox Picture Vocabulary Test (Mage = 103.47, SDage = 8.26, range: 89–120). Using Group-Constrained Subject-Specific (GCSS) analysis, we identified individualized regions of interest (ROIs) engaged during the language localizer, domain-general executive control, and cognitive flexibility tasks separately (thresholded at p < 0.001; Scott & Perrachione, 2019). We then applied Local Pattern Similarity Analysis (LPSA) to compare activation patterns (Pearson’s correlations) between word learning and each task within these ROIs. Correlation values were compared to zero via one-sample t-tests (positive correlations only) to assess co-activation. Within the subject-specific language network, word learning and language processing co-activated the Left Temporal Pole (t(17) = 2.60, p = 0.019), consistent with its established role in semantic memory and conceptual integration (Patterson et al., 2007; Lambon Ralph et al., 2017). Within the domain-general cognitive control network, word learning and cognitive control moderately co-activated the Left Inferior Frontal Gyrus (IFG)/Middle Frontal Gyrus (MFG) (t(17) = 1.86, p = 0.079). This significance trend aligns with prior findings linking the Left IFG to controlled semantic retrieval and conflict resolution (Badre & Wagner, 2007; Novick et al., 2005). Within the cognitive flexibility network, word learning and cognitive flexibility co-activated the Left Lateral Occipital Cortex (t(17) = 2.86, p = 0.011) and Left Supramarginal Gyrus/Angular Gyrus (t(17) = 2.12, p = 0.049). These regions are associated with higher-order conceptual integration and flexible semantic processing (Grill-Spector et al., 2001; Seghier, 2013; Binder et al., 2009). Together, these findings suggest that successful auditory word learning relies on the coordinated engagement of language, cognitive control, and flexibility networks, supporting dynamic integration of new words into existing semantic frameworks.
Topic Areas: Language Development/Acquisition, Control, Selection, and Executive Processes