CONTEXT AND PAVLOVIAN CONDITIONING

Procedurally, learning has to occur in a context, Several lines of evi dence suggest that contextual stimuli actively affect learning and exp ression of the conditional response. The experimental context can beco me associated with the unconditional stimulus (US), especially when th e US is presented in a context in the absence of a discrete conditiona l stimulus (CS). Moreover, context can modulate CS-US associations, Fi nally, it appears that context can become associated with the CS when it is presented before the CS-US training. The purpose of the present paper is to review some of the relevant literature that considers the context as an important feature of Pavlovian conditioning and to discu ss some of the main learning theories that incorporate the context int o their theoretical framework. The paper starts by mentioning historic al positions that considered context an important variable in conditio ning and then describes how the approach to contextual conditioning ch anged with the modem study of Pavlovian conditioning. Various forms of measurement of context conditioning are presented and the associative strength attached to context in several experimental paradigms is exa mined, The possible functions that context may acquire during conditio ning are pointed out and related to major learning theories. Moreover, the effect of certain neurological manipulations on context condition ing is presented and these results are discussed in terms of possible functions that the context might acquire during Pavlovian conditioning . It is concluded that contextual stimuli acquire different functions during normal conditioning. A procedure in which animals are exposed t o an aversive US immediately after they are placed in the experimental context is suggested as a useful control for the study of context con ditioning.