Tectal processing of visual signals from the caudalmost part of the frog visual field.

Electrophysiological investigations restricted to the caudomedial part of the optic tectum show that the caudalmost part of the frog's visual field appears preferentially analyzed by class-2 and class-3 retinal ganglion cells and integrated by monocular T5 neurons even though this spatial region is seen by the two eyes and doubly represented on each tectum. This apparent preponderance for three types of contralateral visual units is discussed on the basis of the animal's behaviour.