Influencia del bilingüismo simultáneo y secuencial sobre el control ejecutivo y la reserva cognitiva

Abstract

The main objective of this research has been to analyze the influence of simultaneous and sequential bilingualism as a possible protective factor of the executive functions in people over 60, once other variables of possible confusion have been controlled, and in comparison with a group of monolingual participants. For this purpose, a quasi-experimental and transversal ex post facto design was followed in which 90 people participated, 30 older monolinguals (15 women and 15 men, age = 66.33; SD = 3.44) and 60 bilinguals. Of the latter, 30 were considered simultaneously bilingual (15 females and 15 males, age = 71.30; SD = 5.12), and 30 were sequentially bilingual (15 females and 15 males, age = 69.33., SD = 4.34). The variables MMSE, age, educational level and socioeconomic level were analyzed and discarded as confounding variables. Neuropsychological tests were used to evaluate executive functions, TMT in its two forms (A) and (B), Zoo Map (BADS), TCD in its two scores (flexibility and inhibition), WMS-III direct order digit test, WMS-III inverse order digit test. The results obtained show that bilingual people, both simultaneous and sequential, have a better executive performance than monolingual people. It was also evidenced that the age of acquisition of the second language influenced the executive performance, favoring those who had earlier contact with their L2. It was also found that the higher (voluntary) frequency of language change was related to better performance in executive functions. The best predictor of executive functions in bilinguals has been the score obtained in the cognitive reserve. Likewise, the best predictor of this reserve is the composite score of the executive functions. Another interesting contribution of the study is that the predictors of executive functions, in the case of simultaneous and sequential bilinguals, are different. For simultaneous bilinguals the second predictor is the frequency of contextual change (CS), while for sequential bilinguals it was the frequency of involuntary change (US). It is also interesting to note that, when analyzing the total sample set, without differentiating between bilinguals and non-bilinguals, again the best predictor of executive functions is the cognitive reserve and viceversa. Finally, it is concluded that bilingualism exerts a protective factor on executive functioning and on cognitive reserve in the elderly. Bilinguals of this age perform better than monolinguals in executive functions, and within bilinguals, simultaneous bilinguals perform better than sequential bilinguals.