Visual discrimination in the toad

Using a method of successive discrimination, 10 toads (Bufo bufo), were trained to discriminate between horizontal and vertical rectangles each 5.0 ± 7.5 cm. After training, one optic nerve was severed in certain animals and the stumps pushed well apart to delay regeneration. The non-operated animals retained their learning over the rest-period of 10 weeks at a level similar to training. The animals with one eye showed considerably less retention than the non-operated animals.