FLUCTUATION OF OPTIC: EVOKED POTENTIALS DURING CONDITIONED AVOIDANCE BEHAVIOR IN CATS: EFFECTS OF ATTENTION AND DISTRACTION ON PRIMARY EVOKED POTENTIALS

S ummary Seven cats with chronically implanted electrodes were trained to learn conditioned avoidance behavior, and changes of the cortical evoked potentials to repetitive optic nerve stimulation during that behavior were observed in two experimental situations; (1) CS was buzzer and (2) CS was the optic nerve stimulation itself. And the changes were compared in the same animals. (1) Repetitive stimulation of the optic nerve was capable of becoming the conditioning signal which induces the cat to perform the avoidance movement. Even with 1 c/sec. stimulation, the cat was able to respond to it within 5 seconds. (2) Grouped facilitations of the evoked potentials intermittently appeared during conditioned behavior. Except for the initial augmentation of the potentials following the onset of CS, there was no distinct difference between the two experimental situations. The initial augmentations were associated with the startle or orientation reflex of the animal and, when buzzer was used as a CS, their latencies were shorter than in the case in which optic nerve stimulation was used as a CS. Whether buzzer or optic nerve stimulation was used as a CS, augmentations of the evoked potentials were highly associated with the animal's aroused behaviors; startle, looking around, intention to move, etc. (3) A comparison was made of the evoked potentials during successful and failed avoidance behaviors with optic nerve stimulation as CS. Mean amplitude of the responses in avoidance group was greater and the variability of the responses was smaller than in non‐avoidance group. On the basis of the above data, it is considered that the fluctuation of the primary cortical evoked potentials to optic nerve simulation might be related with nonspecific arousal level of the animal rather than sense‐modality‐specific attention effect.