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Temporo-Parietal High-Gamma Dynamics of Semantic Interference During Speech Production: Evidence from Stereo-EEG
Poster Session B, Wednesday, September 30, 4:30 - 6:30 pm, Wangari Maathai
Chen Feng1, Xilei Zhang1, Jiaran Dong1, Luyao Wang2, Youting Lin3, Yanliang Sun2, Yi Jiang1; 1State Key Laboratory of Cognitive Science and Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China, 2Faculty of Psychology, Shandong Normal University, Jinan, 250358, China, 3Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
Semantic interference in speech production is thought to reflect competition between target and competing lexical representations; however, its dynamic neural mechanisms remain poorly understood. The present study investigated the oscillatory dynamics underlying the classic semantic interference effect using a picture–word interference (PWI) paradigm combined with stereo-electroencephalography (sEEG). Valid sEEG recordings from eight epilepsy patients were analyzed. Time–frequency analyses focused on high-gamma activity (70–150 Hz), and semantic interference effects were examined at the individual level using cluster-based permutation tests to compare semantically related and unrelated distractor conditions. Results revealed significant high-gamma activities associated with semantic interference predominantly within temporo-parietal regions, including the middle temporal gyrus, superior temporal gyrus, inferior parietal lobule, and supramarginal gyrus. Importantly, these effects showed a temporal progression, with temporal activity emerging earlier than parietal activity. Earlier temporal lobe responses may reflect interactions between target conceptual activation and competing lexical representations during lexical-semantic processing, whereas later parietal involvement may indicate subsequent integrative processes related to language production, including mapping and maintenance across levels of lexical representations. Together, these findings suggest that semantic interference during speech production is supported by a temporally organized temporo-parietal network rather than a single cortical locus. This ongoing study provides preliminary intracranial evidence for the neural dynamics of semantic interference in speech production and highlights the utility of high-gamma oscillatory activity for characterizing the spatiotemporal organization of lexical selection.
Topic Areas: Language Production, Control, Selection, and Executive Processes