Costa, A. , Hernandez, M. , Marne, P. & Pina, V.
Departament de Tecnologies de la Informació i les Comunicacions, Universitat Pompeu Fabra, Spain
Mechanisms of bilingual language control partially overlap with the general-domain executive control system (Abutalebi & Green, 2007). Since executive control abilities decline with ageing (e.g., McDowd & Shaw, 2000), the question is whether bilingual language control also does. The aim of this study is to test this hypothesis by means of the language switching task used by Costa and Santesteban (2004, 2006). These authors have consistently found that switching from the second to the first language is harder than vice versa for low proficient bilinguals, while highly proficient bilinguals always show a symmetrical switching cost (e.g., Costa & Santesteban 2004). In the present study the picture naming performance of 10 young (20-30 y.o.) and 10 elderly (62-73 y.o.) highly proficient Catalan-Spanish bilinguals is explored. The young group showed the symmetrical switching cost repeatedly found for highly proficient bilinguals. Interestingly, however, the elderly group showed a clear asymmetrical switching cost similar to the one typically found for low proficient bilinguals. This pattern of results suggests that the ability of preventing interference between languages changes across the lifespan, being affected by ageing. We discuss the implications of these results for the current theories on bilingual language control.