THE EFFECT OF LESIONS OF THE VISUAL SYSTEM ON PHOTIC DRIVING

Abstract

By means of intermittent photic stimulation of the retina a series of synchronous impulses are found to traverse the visual pathways. These were recorded from the occipital region of the scalp of monkeys by electroencephalography. To study this bioelectrical phenomena "photic driving" lesions were made in various portions of the visual pathways. The lesions largely involved the macular areas of the following regions: retinal, optic tracts, and the striate cortex. The marked impairment of driving was somewhat similar regardless of the site of the lesion. A specificity of response to various colors, especially red and blue, is thought to offer a method of studying the physiology of color vision. When applied to LeGros Clark''s speculations of the lamination of the lateral geniculates as an anatomical correlate to the trichromatic Young-Helmhotz theory, no support for this assumption was found. Bilateral temporal lobectomy without damage to the visual pathways definitely enhanced photic driving.