The effects of latent inhibitory processes on subsequent conditioning : temporal factors and order phenomena

Abstract

Some interference theories of extinction assert that the conditioned response decrement results from the attachment of incompatible associations to a stimulus which formerly had a strong tendency to evoke the conditioned response. In Chapter I, it is argued that this type of theory implies that the incompatible associations acquired via the extinction procedure will be subject to pro-active inhibition by virtue of the fact that extinction forms the second stage of an A-B, A-D negative transfer paradigm. On these grounds, it is possible to interpret the apparent retardation of extinction by spaced trial intervals, and the spontaneous recovery of the conditioned response with rest, as order effects resulting :from pro-active inhibition. The possible confounding of extinction phenomena by order effects limits understanding of the extinction process. This thesis stresses the importance of reversing the two stage conditioning-extinction sequence. An initial series of unreinforced presentations of a stimulus followed, at a later stage, by a series of reinforced presentations of that stimulus, constitutes a procedural reversal. This reversal is referred to herein as the latent inhibition paradigm, and is considered as a possible counterbalanced arrangement for assessing order effects in. extinction. Studies, prior to the inception of the programme of research outlined in this thesis, were not viewed in this perspective. Nevertheless, these early studies, which are reviewed in Chapter II, had shown that initial unreinforced exposure of the CS inhibits subsequent conditioning, Moreover, it becomes apparent in the review of the literature, that this inhibitory effect is not necessarily contingent upon the pre-exposure and the conditioning phases being given in a single session. Hence, it seemed appropriate to infer that the inhibitory process, underlying the effects of initial unreinforced presentations of the CS, has elements of permanence(that is, learning characteristics),… Show more