Summary

Latent inhibition and habituation are behavioural phenomena that result from the same simple procedure: when an animal receives exposure to a stimulus, the unconditioned responses that were once provoked by that stimulus diminish or habituate, and subsequently the rate at which conditioned responding can be established to the stimulus is reduced. One parsimonious interpretation of these phenomena is that they reflect the operation of the same attentional process: a novel stimulus attracts attention, provokes responding and is rapidly learnt about; exposure to a stimulus produces a decline in attention and concomitant reductions in responding and learning. Here, we present an integrative review of recent research that provides support for a specific account of habituation and latent inhibition that is grounded in a formal analysis of the mnemonic processes involved in associative learning. This analysis also provides one interpretation of the role of the hippocampus, a structure traditionally associated with both mnemonic and attentional processes, in habituation and latent inhibition.

Introduction

Latent inhibition (LI) is a phenomenon in both senses of the word: it is a very simple and ubiquitous behavioural effect, and it has stimulated intense empirical and theoretical interest, and some controversy over a protracted period. After a faltering start (see Lubow, this volume), the observation first reported by Lubow and Moore (1959) has become a central concern for theoretical analyses of associative learning: once its generality had been established, LI became the territory of models of associative learning wherein variations in attention play a key role (e.g., Lubow, 1989; Mackintosh, 1975; Pearce & Hall, 1980).