Units Sensitive to Direction of Movement in Goldfish Optic Tectum

Abstract

THE retinæ of frog¹, rabbit², and pigeon³ have recently been shown to contain a variety of ganglion cells which signal the direction in which stimuli cross the visual field. The response of such units to a small stationary spot of white light which is briefly flashed at some point within the receptive field has been generally found to be ON–OFF everywhere within the sensitive area^2–4. Recently, certain units have been found in the retina of the goldfish, Carassius auratus, which give a similar pattern of response to stimulation with small stationary spots of white light⁵. However, in the goldfish, no attempt has been made to examine the response of these units to stimuli other than to brief flashes of stationary spots of light. The investigation recorded here examines the response to more complex visual stimuli, and especially the response to moving visual objects.