Language effects in second language learners and proficient bilinguals investigated with event-related potentials.

The present study examines language effects in second language learners. In three experiments participants monitored a stream of words for occasional probes from one semantic category and ERPs were recorded to non-probe critical items. In Experiment 1 L1 English participants who were university learners of French saw two lists of words blocked by language, one in French and one in English. We observed a large effect of language that mostly affected amplitudes of the N400 component, but starting as early as 150 ms post-stimulus onset. A similar pattern was found in Experiment 2 with L1 French and L2 English, showing that the effect is due to language dominance and not language per se. Experiment 3 found that proficient French/English bilinguals exhibited a different pattern of language effects showing that these effects are modulated by proficiency. These results lend further support to the hypothesis that word recognition during the early phases of L2 acquisition in late learners of L2 involves a specific set of mechanisms compared with recognition of L1 words.