Different effects of L1 and L2 phonology on L3 lexical learning: An ERP study

This study investigated the influence of phonological word representations from both first language (L1) and second language (L2) on third language (L3) lexical learning in L1-dominant Spanish–English bilinguals. More specifically, we used event-related potentials (ERPs) to determine whether L1 Spanish and L2 English phonology modulates bilinguals’ brain response to newly learned L3 Slovak words, some of which had substantial phonological overlap with either L1 or L2 words (interlingual homophones) in comparison to matched control words with little or no phonological overlap. ERPs were recorded from a group of 20 Spanish–English bilinguals in response to 120 auditory Slovak words, both before and after a three-day-long learning period during which they associated the L3 Slovak novel words with their L1 Spanish translations. Behaviorally, both L1 Spanish and L2 English homophony facilitated the learning of L3 Slovak words in a similar manner. In contrast, the electrophysiological results of the post-training ERPs, but not the pre-training ERPs, showed an N100 effect for L2 English interlingual homophones and opposite N400 effects for L1 Spanish and L2 English interlingual homophones in comparison to control words. These findings suggest different neurocognitive mechanisms in the use of L1 and L2 phonological information when learning novel words in an L3.