Bilinguals who stutter: A cognitive perspective

Abstract

Purpose: Brain differences, both in structure and executive functioning, have been found in both developmental stuttering and bilingualism. However, the etiology of stuttering remains unknown. The early suggestion that stuttering is a result of brain dysfunction has since received support from various behavioral and neuroimaging studies that have revealed functional and structural brain changes in monolinguals who stutter (MWS). In addition, MWS appear to show deficits in executive control. However, there is a lack of data on bilinguals who stutter (BWS). This literature review is intended to provide an overview of both stuttering and bilingualism as well as synthesize areas of overlap among both lines of research and highlight knowledge gaps in the current literature.

Methods: A systematic literature review on both stuttering and bilingualism studies was conducted, searching for articles containing "stuttering" and/or "bilingualism" and either "brain", "executive functions", "executive control", "motor control", "cognitive reserve", or "brain reserve" in the PubMed database. Additional studies were found by examining the reference list of studies that met the inclusion criteria.

Results: A total of 148 references that met the criteria for inclusion in this paper were used in the review. A comparison of the impact of stuttering or bilingualism on the brain are discussed.

Conclusion: Previous research examining a potential bilingual advantage for BWS is mixed. However, if such an advantage does exist, it appears to offset potential deficits in executive functioning that may be associated with stuttering.

Keywords: Bilingualism; Brain; Brain reserve; Cognitive reserve; Executive control; Executive functions; Stuttering; motor control.