Previous research has shown that instrumental training can encourage the formation of binary associations between the representations of the elements present at the time of learning, that is, between the discriminative stimulus and the instrumental response (the S-R association), between the stimulus and outcome (the S-O association), and between the response and outcome (the R-O association). Studies with rats have used transfer procedures to explore the effects of discriminative extinction (i.e., extinction that is carried out in the presence of the discriminative stimuli) on these three binary associations. Thus, a reduction in the response rate of the extinguished response (R) can be detected in situations involving a different discriminative stimulus that was associated with the same outcome, and to unextinguished responses controlled by the discriminative stimulus (S) and associated with the outcome (O). These transfer effects suggest that R-O and S-O associations remain active after extinction in nonhuman animals. We carried out an experiment to explore these postextinction transfer effects in humans using a within-subject design. Contrary to nonhuman reports, the S-O association was affected by discriminative extinction, suggesting differences in the associative structure of instrumental conditioning in human and nonhuman animals that should be considered by those therapeutic strategies based in nonhuman animal research aimed to reduce unhealthy instrumental behaviours in human beings.
Public Significance StatementAnimal research has shown that when a response stops being followed by an outcome (i.e., when it is extinguished), the underlying associations that maintained that response remain active. The experiment presented here reveals that extinction of human voluntary responding may be an exception to this general rule, a result that is quite relevant from a clinical point of view, as most psychological treatments involve some form of extinction.