Learning and transposition of an extended sameness-difference concept by slow and fast learning capuchin monkeys

Capuchin monkeys were trained on a series of learning-set problems which required discrimination between stimulus arrays having ABA and BBA configurations. Transposition was later tested by presenting training configurations with CCC or ABC configurations. Considerable negative transposition and a small amount of positive transposition occurred, a result suggesting that the original learning set was based at least partly on perceived differences in the homogeneity of the ABA and BBA configurations. Fast-learning subjects manifested more persistent random responding and less position responding than did slow-learning subjects. This difference suggests that random responding during the initial stages of learning may be used as an index of attention.