Pattern processing and slow-wave activity in visual cortex of cat.

Abstract

Animal models play a significant role in research on human disorders. In vision research, the recording of single-neuron activity from animals has been of great value to our understanding of pattern processing mechanisms. In humans, investigations of visual function have typically utilized slow-wave activity. We have studied in cats the relationship between pattern processing and the slow-wave evoked response recorded from cortical areas 17, 18, 19 and 4 in the awake cat. We have found that within a restricted latency range the response in 17, 18 and 19 reflects the processing of the patterness of a visual stimulus. A comparison of response components occurring prior to 50 msec poststimulus showed few significant differences (P less than 0.05) between peak amplitudes evoked by a diffuse and a checkerboard pattern stimulus. A much higher proportion of response components occurring after 50 msec but prior to 300 msec poststimulus were significantly different (P less than 0.05). The response recorded from area 4 (motor cortex) did not show significant differences as a function of the diffuse and patterned stimuli. Our findings show that the slow wave recorded from cat visual cortex can reflect the pattern processing mechanisms of visual cortex. Since slow waves are used in the study of visual functions in humans, the slow wave may have an important role to play in animal models of visual disorders in humans.