[Comparative pathology of higher nervous activity]

In experiments with defensive behaviour, using multiparametric recording of indices, studies have been made on the origin and development of pathological disturbances in the higher nervous activity of insectivores, carnivores and primates during presentation of difficult conditioned reflex problems or extreme stimulation. It was found that elaboration of absolute differentiation retarded conditioned reactions with a delay of 25 s in insectivores is a difficult task which results in pathological changes in the higher nervous activity. In hedgehogs, neurotic changes are immediate, all the investigated indices being affected. In carnivores, especially in primates, the onset of evident pathological changes is preceded by a long preneurotic period, i.e. a stage of self-regulation. In pathological process, more corticalized forms of the nervous activity are initially involved. Common features and differences in the development of pathological changes in the higher nervous activity among mammals are discussed.