[Electrographic activity in rats during elaboration of fine distinctions]

A definite correlation has been found between the background EEG, the sensory afterdischarge (SAD) of the visual cortex and the nature of the animals' behaviour. Calmer rats with a well pronounced SAD exhibited activation of a certain type of hygienic movements, as fine differentiations were presented. As a rule, the movements were accompanied by EEG synchronization. At the same time positive conditioned reflexes persisted, in spite of an increased number of collisions. In restless animals, as the stress situation became stronger, forced movements appeared against the background of EEG desynchronization with a slightly pronounced SAD, alternating with numbness and stupor. Conditioned reflexes disappeared for several weeks. It has been assumed that relative retention of temporary connections in stress situations in animals with a well pronounced SAD is linked with the defensive-stabilizing nature of the inhibitory synchronized EEG rhythms.