Within-language lexical interference can be resolved in a similar way to between-language interference

This study asks if monolinguals can resolve lexical interference within a language with mechanisms similar to those used by bilinguals to resolve interference across languages. These mechanisms are known as bilingual language control, are assumed to be at least in part top-down, and are typically studied with cued language mixing, a version of which we use here. Balanced (Experiment 1) and nonbalanced Spanish-English bilinguals (Experiment 2) named pictures in each of their languages. English monolinguals from two different American cities (Experiments 3 and 4) named pictures in English only with either basic-level (e.g., shoe) or subordinate names (e.g., sneaker). All experiments were identically structured and began with blocked naming in each language or name type, followed by trial-level switching between the two languages or name types, followed again by blocked naming. We analyzed switching, mixing and (introduced here) post-mixing costs, dominance effects and repetition benefits. In the bilingual experiments, we found some signs of dominant deprioritization, the behavioral hallmark of bilingual language control: larger costs for dominant- than for nondominant-language names. Crucially, in the monolingual experiments, we also found signs of dominant deprioritization: larger costs for basic-level than for subordinate names. Unexpectedly and only in the monolingual experiments, we also found a complete dominance reversal: Basic-level names (which otherwise behaved as dominant) were produced more slowly overall than subordinate names. Taken together, these results are hard to explain with the bottom-up mechanisms typically assumed for monolingual interference resolution. We thus conclude that top-down mechanisms might (sometimes) be involved in lexical interference resolution not only between languages but also within a language.