Abstract
Understanding the neurocognitive architecture underlying third language (L3) acquisition is essential for refining models of multilingual lexical processing and optimizing instructional methodologies. This study investigates the electrophysiological correlates of cross-linguistic semantic priming during novel vocabulary processing in multilinguals. Using high-density event-related potentials (ERPs), we examined 34 native German speakers (L1) with advanced English proficiency (L2) who were actively acquiring Spanish (L3) at an intermediate level. Participants completed a cross-modal semantic priming lexical decision task in which visual L3 Spanish targets were preceded by semantically related or unrelated auditory primes in either L1 German or L2 English. Electrophysiological recordings focused on the N400 component (350–550 ms post-stimulus onset), an established neurobiological index of semantic retrieval and integration effort. The results revealed significant N400 amplitude attenuations for related relative to unrelated conditions across both prime languages. Crucially, L2 English primes elicited earlier and robustly modulated N400 effects for L3 targets compared to L1 German primes, suggesting privileged lexical-semantic routing between the chronologically later-acquired non-native languages. These findings provide empirical support for the L2 Status Factor and the Multilingual Interactive Activation (MIA) framework, demonstrating that L3 lexical integration in adult learners is heavily mediated by non-native interlanguage networks. Implications for multilingual pedagogy and vocabulary instruction are discussed.
