Some Observations on the Superior Colliculi of the Cat by J. Altman

Abstract

The observations I should like to communicate to you in this discussion on the optic tectum were made by Dr. Joseph Altman in the course of his work for a doctoral dissertation². Dr. Joseph Altman undertook these studies for three reasons:

• 1. Just as Professor Doty, he believes that the optic tectum may play a greater role in the visually-guided behavior of carnivores and primates than has usually been assumed. His electrophysiological and subsequent anatomical studies were preliminary to behavioral experiments which are now in progress; his current work is concerned with changes in visual performance after removal of the superior colliculi and adjacent structures.

• 2. The superior colliculi raise a particular problem for correlating structure and function, because of their lamination. As Walls (2) has pointed out, such lamination is found in neuroretina, superior colliculi, lateral geniculates and cortex; eventually, we should be able to account for the “purpose” of these laminar arrangements.

• 3. Lastly, there is the recurrent problem of the interaction which one assumes exists between superior colliculus and visual cortex. In his somewhat preliminary electrophysiological studies (in deeply barbiturized animals), Dr. Altman found no direct signs of such interaction, but subsequent investigation of anatomical connections, by means of the Nauta stain, revealed a definite corticifugal pathway (Altman and Carpenter, in preparation). However, these recent studies with the Nauta stain did not disclose any corticipetal fibers from the cat’s superior colliculus to its visual cortex.

From the Department of Psychiatry and Neurology, New York University College of Medicine.