Аннотация:The psychophysiological signs of aging were studied in F1 (C57BL/6 x DBA/2) mice at the age of 3, 7, and 14 months. It was found that cognitive abilities, memory, and spatial orientation in all animals did not depend on age; they were able to form a four-link food-getting habit. The instability of behavior in the form of the periodic reproduction of mistaken and irrational decisions found in all mice at the stereotyping stage was determined by the characteristics of basic neural processes: increased excitability and weak inhibition. It was found that a consistent reduction of the excitation phase with aging caused instability of the dominant state and motivational activity, negatively affecting attention and, hence, the ability to reproduce consistently the optimal habit variant.