THE FUNCTION OF THE CALLOSAL CONNECTIONS OF THE VISUAL CORTEX.

There is anatomical evidence in cats and baboons of cells at the margin of area 17 which have callosal connections to corresponding points in the opposite hemisphere. The function of such a pathway has been studied in cats after one optic tract has been cut. The corresponding hemisphere now gives early visual responses only at the margin of area 17. Such responses can only be elicited by light stimuli near the vertical meridian of the visual field. These responses are abolished by cooling the corresponding points in the opposite hemisphere and by cutting the corpus callosum. This pathway appears to provide some functional union for the two halves of the visual field.