[On factors that effect the variability of central mechanisms of bilingualism]

The article discusses the probable role of many factors that determine the individual variety of neurophysiological mechanisms, which provide the opportunity to learn and free use two or more languages. The formation of a speech functions is affected by both the general factors for bilinguals and monolinguals, as well as the specific characteristic of the situation of bilingualism. The general factors include genetic and environmental impact of explaining the diversity of individual options for the development of morphofunctional organization of speech functions. A bilinguals, obviously, have even more wide variance of the central maintenance of speech activity, due to the combination of different conditions that influence the language environment, which include the age of the second language acquisition, the language proficiency, linguistic closeness of the languages, the method of their acquisition, intensity of use and the scope of application of each of the languages. The influence of these factors can mediates in different ways by the individual characteristics of the bilingual's brain. Being exposed to two languages from the first days of life, the child uses for the development of speech skills of the unique features of the brain, which are available only in the initial stages of postnatal ontogenesis. In older age mastering a second language requires much more effort, when, as maturation, the brain acquires new additional possibilities, but permanently lose that special "bonus", which nature gives a small child only in the first months of life. Large individual variability patterns of activation of the cortex when verbal activity in late bilingual" compared with the "early", allows to assume, that the brain of "late bilingual", mastering a new language, forced to operate a large number of backup mechanisms, and this is reflected in the increase of variation in the cerebral processes, responsible for providing of speech functions. In addition, there is serious reason to believe that learning a second language contributes to the expansion of the functional capabilities of the brain and creates the basis for a successful cognitive activity.