Pavlov's Position on Old Age within the Framework of the Theory of the Higher Nervous Activity

In the 1920s, as I. P. Pavlov was growing old, he began to show interest in the general process of aging. In order to study senescence, Pavlov and his disciples experimented in the laboratory on old dogs by the method of salivary conditioning and also observed aged psychotic patients in the psychiatric clinic. Pavlov never formulated a theory of aging per se, but incorporated his findings on aging into his theory of higher nervous activity, which dealt with the function of the brain in higher organisms' adaptation to the environment. Some of the major findings showed that salivary conditioning and stimulus differentiation were difficult to establish in old dogs. Conditioned reflexes established earlier in dogs' lives, however, persisted into old age. Pavlov explained these findings in terms of hypothesized neural processes in the brain; with age, neural processes deteriorate and their reactivity to the environment wanes. In light of more recent research, Pavlov's views on senescence, with the exception of the relation of conditioning to aging, are mainly of historical interest.