Calabria, M. 1 , Hernandez, M. 1 , Marne, P. 1 , Juncadella, M. 2 , Reñé, R. 2, 5 , Ugas, L. 3 , Bertran, S. 3 , Lleó, A. 4 , Blesa, R. 4 & Costa, A. 1, 5
1 Universitat Pompeu Fabra, Department de Tecnologia, Barcelona, Spain
2 Unitat de Diagnòstic i Tractament de Demències, Servei de Neurologia de l’Hospital, Universitari de Bellvitge, Spain
3 Hospital General de Granollers, Spain
4 Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
5 Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
Bilinguals are faster to produce words in their first language (L1) when the distractor word corresponds to the target’s translation (L2) than when the distractor is an unrelated word. This cross-language identity facilitation effect has been observed with different paradigms in young bilinguals. Could this facilitation in lexical competition be abolished in patients with an impaired cognitive control? To test this assumption we used a cross-language version of the Stroop task in three groups of Catalan-Spanish bilinguals, such as: older adults, mild cognitive impairment and Alzheimer disease patients. Participants were required to name colour in Catalan with three types of Spanish words: the name of the colour, the name of a different colour and the name of an unrelated adjective.
Older adults and patients showed the same amount of cross-language identity facilitation, such as ~ 35 ms faster to name colour in L1 when the distractor word in L2 was the name of the colour than when it was an unrelated word. The magnitude of this effect is as high as that was found in young adults. Slower naming latencies were found when participants had to name words with a name of different colour. This interference effect was larger for MCI (255 ms) and AD (308 ms) compared to older adult controls (177 ms).
It is concluded that dementia does not affect the lexical competition during speech production since the cross-language identity facilitation was reliable in patients as in older controls. So, Alzheimer disease patients do not suffer of the L2 interference at the lexical level when they have to produce words in L1.