Second-language experience modulates first- and second-language word frequency effects: evidence from eye movement measures of natural paragraph reading.

We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate whether the degree of current L2 exposure modulates the relative size of L1 and L2 frequency effects (FEs). The results showed that bilinguals displayed larger L2 than L1 FEs during both early- and late-stage eye movement measures, which are taken to reflect initial lexical access and postlexical access, respectively. Moreover, the magnitude of L2 FEs was inversely related to current L2 exposure, such that lower levels of L2 exposure led to larger L2 FEs. In contrast, during early-stage reading measures, bilinguals with higher levels of current L2 exposure showed larger L1 FEs than did bilinguals with lower levels of L2 exposure, suggesting that increased L2 experience modifies the earliest stages of L1 lexical access. Taken together, the findings are consistent with implicit learning accounts (e.g., Monsell, 1991), the weaker links hypothesis (Gollan, Montoya, Cera, Sandoval, Journal of Memory and Language, 58:787-814, 2008), and current bilingual visual word recognition models (e.g., the bilingual interactive activation model plus [BIA+]; Dijkstra & van Heuven, Bilingualism: Language and Cognition, 5:175-197, 2002). Thus, amount of current L2 exposure is a key determinant of FEs and, thus, lexical activation, in both the L1 and L2.