Екітілділік және когнитивтік даму: Эллен Биалисток зерттеулері

Canadian psychologist

Ellen Bialystok, OC, FRSC (born 1948) is a Canadian psychologist and professor. She carries the rank of Distinguished Research Professor at York University in Toronto, Ontario where she is director of the Lifespan Cognition and Development Lab. She is also an associate scientist at the Rotman Research Institute of the Baycrest Centre for Geriatric Care.

Much of Bialystok's current research concentrates on bilingualism from childhood through older adulthood and aging, and its effects on cognitive processes over the lifespan. She has also studied aspects of language acquisition in children, both in written and verbal forms, and how bilingualism might affect these processes.

Bilingualism has been shown through various studies to have a significant effect on certain aspects of cognitive development, especially in comparison to that of monolingual individuals. Bialystok has investigated this idea further, attempting to figure out what parts of cognitive development, specifically, are affected by bilingualism. Children are of particular interest to this realm of research, as she studies the developmental progression of bilingual children as opposed to that of monolingual children.

While bilingualism has repeatedly been shown to affect cognitive development, research has been less focused on which aspects of cognitive development, in particular, are affected. Bialystok and Barac, in a study about the generality of bilingual effects on development, compared three groups of bilinguals to one group of monolinguals in a series of linguistic tasks and one nonlinguistic, executive control task involving task switching. The three bilingual groups differed according to three factors: similarity between languages spoken, cultural background, and language of educational experience. All three bilingual groups outperformed the monolingual group on the task switching executive control task, however, even in excluding the monolingual group, neither of the three differentiating factors had a significant effect on the performance of the executive control task. These results suggest that bilingualism itself provides an advantage in the nonverbal, executive control aspect of cognitive development. Beyond this general advantage to cognitive development seen in bilinguals, there is remarkable evidence for an advantage regarding executive control in particular – specifically in cases where multiple components of this executive control is required for perform a task. Children's progress in their development of both English and French linguistic and metalinguistic skills were examined to assess how accurately their developing abilities matched those of fully bilingual children (those who had learned their second language at home), and whether or not the intensive French immersion was impeding their English language development. While the analysis of tasks concerning linguistic and metalinguistic abilities in both French and English found a variety of different patterns, many of those patterns matched that of the fully bilingual children. Thus, these children participating in this immersion program are not only able to truly become bilingual, but gain the advantages that come with bilingualism as well. Continued exposure to French as well as instruction in the formal structures of the language should only improve upon these children's developing linguistic skills. Results demonstrated two different types of processing. Phonological awareness, which was strongly correlated across the two languages, suggests a common cognitive basis regardless of the language being learned. Word identification, in contrast, did not relate across the two languages, suggesting a specific ability governed by each individual language and its particular demands. In the case of bilingual children learning to read two different writing systems, phonological awareness appears to be a more generalized ability that can be transferred easily across languages, while word identification (and therefore reading) must be developed separately for each language. In the response inhibition condition, both the monolinguals and bilinguals activated the same neural network and performed the task in the same amount of time. However, in the interference suppression trials, bilinguals activated different neural regions than monolinguals and also performed the task more quickly. The distinction in neural response between monolinguals and bilinguals indicates not only that interference suppression and response inhibition are cognitively distinct from one another, but also supports the idea that bilingualism provides an advantage in the cognitive control of inhibition concerning conscious attention (manual key pressing), but doesn't not seem to have a significant effect regarding the control of more instantaneous motor responses (inhibition of eye movements). Further work was done with groups of younger and older monolingual and bilingual adults in three consecutive studies investigating the persistence of the bilingual advantage into adulthood, as well as the notion that bilingualism provides a defense against the deterioration that aging brings on executive control. Bialystok, Craik, Klein, and Viswanathan found that results indicated a continuation of the bilingual advantage into adulthood, and a pattern that suggests a slowing of age related decline in executive processes for older bilingual adults along with other positive effects in cognitive functioning, suggesting widespread benefits of bilingualism beyond what was originally hypothesized.

The natural process of aging has a deteriorating effect on the brain, and commonly leads to detrimental conditions such as dementia or more specifically, Alzheimer's disease. With the bilingual advantage that appears to persist throughout a person's lifespan, it is plausible that symptoms of these conditions could be offset or further delayed by the lifelong advantages brought about by bilingualism.