• the concept of two qualitatively different stages in Human Life-Span Development, and two types of aging,

• a model of Human Life-Span Development, or the "Individuality concept" as it is often referred to.

Ananiev's concept of Human Sensory-Perceptive Organization

In contrast to ideas dominating in the international science in the 1960s, Ananiev rejected the nativist view of sensory processes and sensory development. Ananiev insisted that sensory-perceptive processes belong to the core phenomena of life activity inextricably linked to the holistic structure of human personality development. Developing the ideas of Vygotsky's socio-cultural theory Ananiev argued that in the course of human life all psycho-physiological functions undergo a general reconstruction, so that the adult human brain and human body as a whole becomes an integrated system fit for the typical forms of activity of the individual. This idea was proved in many wide-scale experimental investigations of Ananiev (1960; 1961; 1968a). In his experiments he proved that in adulthood basic physiological functions that are used in typical forms of activity (first of all in professional activity) keep stable and are even in progress for long periods, while the functions that are not used are doomed to degrade quickly with age.

Figure 1. Acoustic discrimination thresholds for three groups of subjects: non-musicians (x), piano players (*), violin players (O)

Most impressive are experimental data concerning effects of professional work on life-span dynamics of perceptual abilities. For example, sensitivity to red and yellow colors in adulthood normally degrades quickly with age. Ananiev and his colleagues showed that workers engaged in steel foundries keep this sensitivity for long periods. Ananiev argued that this is because the workers use their visual color perception to determine the moment when steel is perfectly ready. So the natural regularity of age dynamics is abrogated to promote effective professional activity. Similar effects were shown concerning the stability and even progress of other psychophysical functions used in professional activities: tactile sensitivity taste discrimination, etc.

One example of this experimental research is an experiment performed by Ananiev's colleague K. Kaufman (Ananiev, 1968a), who studied the effects of musical professional work on acoustic discrimination. The aim was to show that being a musician not only requires high perceptual abilities as a starting point, but in itself is a factor promoting specialized development of basic psychophysical functions. Acoustic discrimination was measured for three groups of subjects: non-musicians, piano players, and violin players. In each group the researchers tested adult professionals and children beginning their musical education. Sounds were presented in pairs; the first sound was always the same, at a frequency 435 oscillations per second, and the second sound was the same or a certain interval higher or lower. The task was to say whether the second sound was higher, lower or the same as the first one.