Is adaptation involved in bilingual language production? A fresh look at the assumptions motivating potential bilingual-monolingual differences in adaptive control

One of the hottest debates in psychology-whether bilingual-monolingual differences exist in cognitive control-is at a stalemate. Here we propose that the stalemate could be broken by shifting the research focus from whether those differences emerge to why they should. We offer an example of this approach by testing the assumption of current theories of language-control associations that adaptive control is involved in bilingualism, specifically language production. Unbalanced Italian-English bilinguals living in the Milan area completed a Stroop task in their L1 and a picture-naming task in their L2. Both tasks involved a manipulation of the proportion of the type of stimuli that are assumed to require control, i.e., incongruent stimuli in the Stroop task (e.g., the word RED written in blue) and pictures with noncognate names in the picture-naming task (e.g., the picture of a horse, whose Italian name, "cavallo," has a very different pronunciation). Both confirmatory and exploratory analyses showed a clear dissociation between the two tasks, with the Stroop task producing an interactive pattern indicative of adaptive-control involvement and the picture-naming task failing to produce a similar one. These results suggest that adaptive control may not be involved in bilingual language production and, therefore, may not produce bilingual-monolingual differences in cognitive control. It is hoped that this research will inspire a change in the study of language-control associations, pushing future research efforts towards grounding the assumptions for those associations in empirical evidence.