Selection of Consequences: Adaptive Behavior from Random Reinforcement

The behavior of subjects in a human operant conditioning experiment was “shaped” using a random reinforcement contingency. Bar-press responses kept a moving cursor near a target although the consequence of each response was a random change in the direction of the cursor. The apparent effect of reinforcement on behavior is shown to be an illusion created by ignoring the consistency of behavioral results.

The Effect of Prior Random Reinforcement on Brightness Discrimination Learning in Rats

An experiment is described in which rats were transferred from an insoluble, random reinforcement problem to a brightness discrimination. A second group was given position training under 50% contingent reinforcement before the transfer task. Both treatments produced strong position stereotypes which continued during the transfer task, but learning was significantly slower for subjects which had experienced the insoluble problem. The effect occurred whether or not the brightness cues were present during the initial training, although their presence significantly impaired subsequent learning under both conditions. The results are interpreted in accordance with the hypothesis of learned irrelevance.