Pseudolearners in Discrimination Reversal

This research investigated the shape of the acquisition and reversal functions in retardates' discrimination learning, with safeguards against suspected artifacts in other studies. A modified Wisconsin General Test Apparatus was used with 60 retardates in a 2 × 2 factorial design. Another 11 were classified as pseudolearners. The variables were the prereversal criteria and the number of irrelevant dimensions. After meeting criterion subjects were given 30 more trials for the detection of pseudolearners, but all received reversal training. Performance was stationary in both acquisition and reversal, suggesting all-or-none learning. For learners, differences of midreversal plateaus appeared which were opposite to predictions of the Zeaman and House (1963) theory. When pseudolearners were included, however, the plateau effect partially conformed to the theory.

Color Preference in the Gibbon

Color preference was tested by showing 6 colored objects to one adult gibbon. The subject demonstrated both color and position preferences on a modified Wisconsin General Test Apparatus. The blue object and, during some conditions, responses to the subject's right were most preferred.

Device for Study of Communication of Dominance without Physical Contact

Dominance competition between paired rhesus monkeys ( ns = 4) was compared using a standard apparatus, the Wisconsin General Test Apparatus, and a new device called the Parallel Competition Box. The Parallel Competition Box does not allow physical contact between individual Ss during testing as does the Wisconsin General Test Apparatus. Results comparing the Parallel Competition Box and the Wisconsin General Test Apparatus on food incentive competition indicate that physical contact is not necessary for assertion and maintenance of dominance between socialized rhesus monkeys.

An Apparatus for the Automatic Presentation of Object Discriminations to Monkeys

Object discriminations have traditionally been presented to monkeys by hand in the Wisconsin General Test Apparatus. This method is time-consuming and prone to various kinds of experimenter error. It has proved possible to administer object discriminations automatically by using a modification of the Gloster Saro VM 51 vending machine. This machine, which has space for up to 371 objects, moves them on trays by two electric motors, and the control circuits of these are adapted for external operation by relays and modular programming equipment. A series of simple object discriminations or a concurrent (serial) discrimination task can then be given by remote control. The objects are so treated that by touching either of them the animal completes a circuit, enabling the response to be recorded and appropriately reinforced. Learning in the apparatus seems to be about as efficient as in the Wisconsin General Test Apparatus.

Anxiety, Learning Sets, and Sociopathy

This study attempted to determine if lack of ability to profit from past experience was characteristic of primary or secondary sociopathics. Sociopathic and normal Ss were divided into high- and low-anxiety groups on the basis of the Lykken Activity Preference Questionnaire, the Taylor Manifest Anxiety Scale, and the Welsh Anxiety Index. Using a modified Wisconsin General Test Apparatus, Ss were given a series of problems in order to observe the rate of formation of learning sets, this being one method for determining whether S profits from past experience. “Learning to learn” occurred in all groups. There were no significant differences among the four groups regardless of the anxiety scale used. If either secondary or primary sociopathics do exhibit an inability to profit from past experience, then it may be only in learning situations which involve noxious stimuli.