The Lexical Bias Effect during Speech Production in the First and Second Language

The lexical bias effect is the tendency for people to make phonological speech errors that result in existing words. Several studies have argued that this effect arises from a combination of factors: the self-monitoring system covertly weeding out more nonword than word errors and feedback of activation during speech production biasing towards lexical outcomes. Moreover, lexicality of the context has been shown to influence the occurrence of the lexical bias effect (Hartsuiker, Corley, & Martensen, 2005), supporting a role for monitoring. But how does this process differ in one’s first language (L1) as opposed to this same process in the second language (L2) and is there even a difference to begin with? To address that question, we tested whether people also show the lexical bias effect when speaking in a second language (L2) and if so, whether the effect is also modulated by context lexicality. Additionally, we tested whether recent exposure to existing words in L2 influences such a lexical bias effect. We observed a lexical bias effect in L1 but not in L2 in Experiment 1. Moreover, the lexical bias effect in L1 was marginally modulated by context. Experiment 2, in which more L2 words were presented, did not demonstrate a lexical bias effect in either language. However, an analysis of a subset of the data (namely the blocks that were identical in both experiments and thus directly comparable) found a three-way interaction between Outcome, Language, and Experiment. This interaction suggests a strong lexical bias effect in Experiment 1 for L1 but not for L2 whereas Experiment 2 reveals a comparable lexical bias effect in both languages. This indicates that more exposure to existing L2 words leads to an increase in activation of the lexical representations of the target language, thereby increasing the number of transpositions and therefore an increase in the strength of the lexical bias effect.