Dynamic character and age dependence of functional brain organization in attention.

Intrahemispheric functional organization was studied during a task expectancy period with special reference to attention mechanisms. The estimation of coherence of functionally identical rhythmic EEG components was made to characterize the intracortical integration. Several factors influencing the possibility to make an adequate prognosis and to realize it were varied. Different types of the task (objective factor) were used. Subjects of different ages (7, 9-10 years, young adults) and children of the same age differing by the brain maturity level (subjective factor) were studied. It was shown that all factors studied have a certain influence on the brain organization underlying the task preceding attention. Clear age differences as well as the lag between the possibility to formation and realization of the prognosis in children were observed. Alternative "strategies" used in different ages to facilitate the task performance were analyzed; the underlying mechanisms were discussed.