Haptic to visual cross-modal recognition of objects in the vervet monkey.

Five juvenile vervet monkeys (Cercopithecus aethiops) were tested using the Cowey and Weiskrantz technique. The animals had access in the dark to distasteful biscuits of one shape and tasteful biscuits of another shape. Later they were shown a pair of biscuits, one of each shape, and the animal’s first selection was scored. A single pair of shapes was used with flavor assigned daily according to a Gellerman schedule. In 69 percent of trials the monkeys selected the tasteful shape (P less than 0.001). The performance in the second half of testing was higher than in the beginning which suggests that some kind of learning set develops.