The book is devoted to model ideas about the principles of information processing in the nervous system of animals and humans. Model development combines the analysis of neurophysiology data with the formulation of information transformations in the language of cybernetics. The first part deals with information processes in the neuron. Attention is focused on new data on the active role of dendrites and the modeling of neurons with dendrites of different configuration. The second part is devoted to the auditory system .. The mechanisms of frequency analysis, binaural hearing (passive location), perception of height and rhythm of sound signals. are presented. The third part deals with the visual system .. Concepts of spatial-frequency image analysis, texture separation and binocular fusion. are presented. The book is designed for specialists in the field of cybernetics and neurophysiology, studying information processes in the brain and developing biopic systems.