فاطمه نعمتی

Second-language comprehension involves real-time integration of semantic meaning and syntactic structure. However, the combined effects of verbal argument congruity and cross-linguistic syntactic differences remain underexplored—particularly among Iranian EFL learners whose L1 (Persian) diverges from English in verb–preposition patterns. This study employed event-related potentials (ERPs) to investigate how these factors influence comprehension accuracy and neurocognitive processing. ERP components N400 and P600 were analyzed to index semantic integration and syntactic reanalysis. A total of 180 sentences (120 main, 60 fillers) were presented via rapid serial visual presentation (RSVP) under four conditions: semantically congruent/syntactically similar, congruent/different, incongruent/similar, and incongruent/different. Participants received structured instructions and were asked to read silently without facial movement. Brain responses were recorded and analyzed using MATLAB and EEGLAB. Results showed robust N400 effects for semantically incongruent endings across proficiency levels, indicating sensitivity to semantic violations. In contrast, P600 amplitudes varied with syntactic differences and proficiency: advanced learners exhibited stronger reanalysis responses, while intermediate learners showed reduced sensitivity. These findings suggest that semantic congruity drives N400-mediated integration, whereas cross-linguistic syntactic differences and proficiency modulate P600-mediated reanalysis. The study advances understanding of neurocognitive mechanisms in L2 sentence processing.