Cognitive control and language control in bilingual aphasia: Insights from recent studies

Aphasia is increasingly being studied with respect to its interaction with cognitive control. The diverse manifestations of language impairment observed in bilingual individuals with aphasia point to a disruption of control mechanisms. The hypothesis of an underlying deficit in cognitive control in bilingual aphasia is consistent with Green’s Inhibitory Control Model [1]. According to this model, inhibition plays a significant role in the verbal production of bilingual speakers who must select words from multiple languages. The aim of this review is therefore to synthesize research on the relationship between cognitive and language control in bilingual aphasia. In a narrative review of twenty-six studies, we analyze the clinical and experimental approaches used to assess this relationship, as well as the factors influencing it in the context of bilingualism and aphasia. The results of this review highlight diverse methodologies for assessing the two control domains, as well as heterogeneous performance in bilingual patients with aphasia. This heterogeneity is evident in the functions assessed and the extent to which control is domain-specific versus general. Despite these differences, the results suggest a dysfunction of executive functions, particularly those involved in language control, in these patients. These results must be considered in relation to the severity of the aphasia, the recovery modes, and the premorbid bilingual skills. To better understand the relationship between the two types of control and the factors that influence it, future research should employ more refined methodologies. This will require precise definitions of language control, adapted assessment tools, and more rigorously controlled cohort studies that take into account the multiple factors influencing bilingualism and aphasia.