The influence of predictive accuracy on serial conditioning in the rat

Three experiments with rats examined the strength of approach to a light when serial conditioning was conducted with the sequence light-tone-food, partly to examine the generality of findings obtained previously from pigeons. In Experiment 1 the light was located on the wall of the conditioning chamber. Approach to this stimulus was greater for Group LT + L0, which received serial conditioning intermixed with trials with the light alone, than for Group LT +, which received only serial conditioning, or for Group LT + LT0, which was given serial conditioning together with trials with the light-tone sequence followed by nothing. These results were replicated in Experiments 2 and 3, where the source of the light was moved to the magazine in which food was delivered. Experiment 3 also examined the effects of using the light, after serial conditioning, to signal nonreinforcement in an appetitive discrimination. The discrimination was learned most rapidly by Group LT+L0. The results suggest that approach to a li...