Influence of a brief linguistic immersion on lexical selection processes during speech production: A longitudinal ERP study

Baus, C. 1 , Molinaro, N. 1 , Costa, A. 2 & Carreiras, M. 1, 3

1 Basque Center on Cognition, Brain and Language (BCBL). Donostia. Spain.
2 Universitat Pompeu Fabra
3 Ikerbasque. Basque Foundation for Science

Several studies using the language switching paradigm have reported that the way the two languages of the bilingual speaker are controlled during speech production is modulated by L2 proficiency. The magnitude of the switching cost across languages has been considered an index of how language control mechanisms guarantee lexicalization in the intended language. At lower levels of L2 proficiency, the asymmetrical switching cost (greater for L1) indexes that language selection is ensured by means of inhibitory mechanisms that operate over the non target language (Green, 1998). At higher levels of L2 proficiency, the symmetrical switching cost indexes that language selection does not rely in such mechanisms (Costa, Miozzo, & Caramazza, 1999).
In the present study we explore the extent to which a relatively short time but intensive exposure to a L2 in the immersion context, modulates the way lexical selection processes operate during speech production. To do so, we tested the naming performance within the language switching paradigm (and its electrophysiological correlates) of a group of 36 German learners of Spanish. Importantly, we explored longitudinal changes across time of immersion (by comparing performance at the beginning and at the end of immersion). Results on the immersion effects showed a change in the switching cost, from asymmetrical to symmetrical. Electrophysiologically, we focused on two ERP components related to language control: the N2 and the Late Positive Component (LPC). The modulation of these two components associated to the switching cost changed across time of immersion. For the N2 component, we observed a change in the scalp distribution from anterior to posterior sites, being the effect of time more marked in L2 than in L1. In contrast, for the LPC component, the effect of immersion was observed only in L1. Results are discussed in the framework of speech production models.