SELECTIVE ASSOCIATION FORMATION

SELECTIVE ASSOCIATION FORMATION
A further challenge to the principle of contiguity came in the 1960s when psychologists began to realize that the principle might apply only to certain pairings of events. They had long suspected that some associations might form more readily than others, but they were usually able to find reasons to dismiss their worries. For example, when attempts to replicate Watson’s demonstration of emotional conditioning in infants proved unsuccessful when an inanimate object, rather than a live animal, was used as the CS, researchers suggested that the CS was simply not salient enough to be noticed. But an important experiment by Garcia and Koelling (1966) showed selectivity in association formation that could not be easily explained away. Their study demonstrates the phenomenon of preparedness. [preparedness tendency of certain combinations of events to form associations more readily than others] The rats in this study appeared to be prepared to associate external cues with painful consequences and to associate illness with taste cues. But taste did not become readily associated with shock, nor external cues with illness. The usefulness to the rat of having a learning system that operates in this way should be clear; after all, gastric illness is more likely to be caused by something the rat ate than something it heard or saw. But to the psychologist investigating general laws of learning, the preparedness effect constitutes a problem in need of explanation. One possibility is that a principle of similarity operates in conditioning. [principle of similarity suggestion that association formation occurs particularly readily when the events are similar to one another] By this principle, not only should the events to be associated occur together, but if learning is to take place they should also be similar to one another. Applying this principle to the Garcia and Koelling result, a taste and an illness might be readily associated because they are similar in that both are detected by receptors (called interoceptors) concerned with the animal’s internal environment. External cues, on the other hand, have little in common with an internal state, making it difficult to associate auditory and visual events with illness. Compared with the massive amount of experimental effort that has been expended on establishing the finer points of the contiguity principle, investigation of the similarity principle has been almost totally neglected. Perhaps we will see more studies in this area before too long.