Electrophysiological correlates of the masked translation priming effect with highly proficient simultaneous bilinguals

In the present study, we examined whether there is a symmetrical masked translation priming effect for non-cognate words in a group of highly proficient (native-like) Basque-Spanish simultaneous bilinguals using event-related brain potentials. Participants were presented with a set of Spanish and Basque words that could be preceded by their repetitions (an identity condition), their translations in the other language, or by two unrelated words (one in each language). Results showed a significant masked repetition effect for Spanish as well as for Basque targets, mainly evident in the N250 and N400 components. Interestingly, a masked translation priming effect was also found in the N400 component in both language directions (L1-to-L2 and L2-to-L1). Furthermore, the magnitude of the N400 modulation for the translation priming effect was similar in the two directions. Finally, we also found a language switch cost effect in the N250 and N400 components, associated with primes (related and unrelated) that did not match the target word's language. This language switch cost effect was also highly similar across the two language directions.

Research Highlights
► Balanced simultaneous Basque-Spanish bilinguals show symmetric masked repetition priming ERP effects in the N250 and N400 components.
► Balanced simultaneous Basque-Spanish bilinguals show symmetric masked translation priming ERP effects in the N400 component.
► Balanced simultaneous Basque-Spanish bilinguals show symmetric language switch cost ERP effects in the N250 and N400 components.