Abstract

The present study tried to demonstrate that the context specificity of latent inhibition in classical conditioning is a matter of degree rather than all-or-none phenomenon. Rabbit's nictitating membrane response (NMR) was selected for classical conditioning, and the congruence between the context of stimulus pre-exposure period and that of conditioning period was systematically varied in order to assess its effect on the speed of conditioning. Thirty male New Zealand rabbits were randomly assigned to one of the five groups: a control, a same context, a one-third different context, a two-third different context and a totally different context group (Context consisted of an olfactory, an auditory, a spatial, a temporal and two visual cues. Thus the one-third different context group, for example, means that the context of the conditioning was different from that of the pre-exposure by two cues). Each subject except the control was, then, exposed to a randomly presented 1000-Hz tone 100 times under the respective context in each of three stimulus pre-exposure periods, after which 80 trials of conditioning were conducted in each of four conditioning periods. Results show that as the degree of congruence between the context of stimulus pre-exposure and that of conditioning decreased, the speed of conditioning increased accordingly. It is suggested that the results demonstrate a graded nature of context specificity of latent inhibition in particular, and that the structuring and influence of context upon conditioning be conceptualized in terms of graded scale rather than of all-or-none dichotomy in general.