Dynamic modulation of emotion priming on code-switching comprehension in bilingual sentences: an ERP study of stage-specific neural coupling

This study employed event-related potentials (ERPs) to investigate how emotion priming modulates the comprehension of within-sentence code-switching in Chinese-English bilinguals. Using a dual-task paradigm combining emotion priming and sentence comprehension, we adopted a 3 (emotion: happy, neutral, fear) × 2 (language: L1, L2) × 2 (context: non-switch, switch) within-subjects design. Behavioral results revealed that emotion priming dynamically shaped code-switching costs by reallocating cognitive control resources: negative emotion (fear) amplified the L1 advantage (smaller switching cost compared to L2), whereas positive emotion (happy) attenuated this asymmetry. ERP results demonstrated a stage-specific, dynamically coupled neurocognitive mechanism: during early perceptual encoding (EPN, 100–300 ms), emotion interacted with language type and hemisphere; in the conflict monitoring stage (N2, 180–360 ms), language type dominated, with emotion modulating monitoring sensitivity; during semantic integration (N400, 380–500 ms), language remained central, while emotion and context jointly influenced processing depth; in the late evaluative stage (LPC, 600–850 ms), language and context drove reanalysis, with emotion exerting only selective modulation. These findings reveal a hierarchical “stage-differentiated, dynamically coupled” mechanism through which emotion regulates bilingual code-switching comprehension, offering novel insights into the interplay among emotion, language, and cognitive control in the bilingual brain.