Albino Wistar, pigmented DA and crossbred (F 1 ) rats were compared in learning of 4 versions of a simultaneous circle-triangle discrimination. On tasks with 3 dimensional shapes, either with both visual and tactual cues available, or without the tactual cues, albino rats performed as well as the pigmented rats. On tasks with reduction of visual cues, (one task with 2 dimensional cues, the other with tactual cues, and reduced 3 dimensional visual cues), the albino group's performance was significantly inferior to that of the pigmented rats. The two types of pigmented rats did not differ in learning on any task.
