In the present work age features of psycho-physiological maintenance of mental activity were studied. Functional age and person's aging rate were researched by special method to show overall functional condition of the examinees. In persons of age 21–30 years high level of mental activity is maintained by improving speed and quantity properties of the visual information processing system. In the group of 31–50 years - by enhancing sensomotoric reactions and cognitive functions. The trend of age decline of attention and memory was revealed in scientists of age above 50 years, which results in decrease of mental ability. However, in the group of 61–70 years the reliability of mental activity on the level of the 21–30 years group was revealed. Hence, although the majority of physiological functions are declining, in persons of age above 60 years the level of professional working ability remains stable. This fact confirms the adapt-regulatory theory of aging formulated by Academic V.V.Frolkis.

Moreover, the present research revealed that functional age and person's aging rate were among factors limiting the effectiveness of mental activity. As a result of studying the variability of heart rhythm under influence of intellectual loading there were revealed the interchange processes characterized by nonlinear change of pressure degree of the heart rhythm regulation after 50 years.