[Problems of interpersonal communication in the latter part of life as seen from sensory physiology]

Both, the sensory organs themselves and the central nervous system with its decoding functions for perception of sensory stimuli influence drastically the human ability for social communication especially with respect to the exchange of speech information. Severe hearing loss, e. g., may inhibit the motivation for the continuation of existing social contacts considerably in aging human beings. Additionally the drop of elasticity within the eye's lense influences negatively the visual human interaction with increasing age. Similarly the performance of the somesthetic, the olfactory and the gustatory sensory may drop simultaneously. Since also the physiological conditions for information storage and retrieval are altered in the senium the wellknown social problems of aged people seem to be due rather to the central parts of the sensory channels than to the sensory organs per se. In this context it is of great importance for the avoidance of problems of the human interrelations between older subjects to keep the human brain intellectually trained as long as intensive as possible (E. Jalavisto). The neurophysiological changes within the CNS, therefore, are discussed in this paper as a function of age and in context with the more somato-physiological changes of the circulatory and metabolic processes including humoral, hormonal and biocybernetical transitions between the second and "Third" section of the human life. During senium, as a conclusion, emphasis should be given to the behavioral selection both of contact persons and of intellectual and emotionally loaded topics of interest to improve the quality of this last part of the life under the aspect that "multum" can be more than "multa", "universalistic" filtering of the life's events more than "encyclopedistic" knowledge (Th. Heuss).