PROJECTION OF THE RETINA ON SUPERIOR COLLICULUS OF CATS

Abstract

A systematic projection of the visual field or retina on the superior colliculus of 21 cats was found by means of an electro-physiologic method whereby a 4.2[degree] square of light was flashed for 10 msec. on a known position in the visual field while action potentials evoked by this stimulation of the retina were picked up from 40 points on the surface of each superior colliculus and were recorded on a cathode ray oscillograph. Homonymous half-fields are projected on the contralateral superior colliculus, homonymous field points being superimposed on the colliculus. The vertical meridian is at the anterior margin of the colliculi and lateral field points at the posterior margin. The upper field is medial to the lower field. Points in the visual field near the horizontal and vertical meridians are projected to a wider area on the colliculus than are more peripheral points.