[Recovery cycles of cortical-evoked potentials to paired stimuli].

In chronic experiments on cats, after elaboration of eyelid reflex to clicks, EPs were simultaneously recorded in the auditory, sensorimotor and visual neocortical areas in response to heteromodal paired stimulations with changing interstimuli intervals (click+electro-cutaneous stimulation of m. orbicularia oculi, CS and US). With short interstimuli intervals (up to 50 ms), a stage of sharp EP suppression in the sensorimotor cortex in response to the test electro-cutaneous stimulus was observed. After extinction of the conditioned reflex initial relations were restored: with the same short interstimuli intervals, the EPs to the test electro-cutaneous stimuli were commensurable with those to the isolated application of the current. The data obtained are considered as electrographic sign of the synthetic nature of the conditioned reflex formation.