Does contextual change determine long-term forgetting?

A series of experiments were run to test the hypothesis that “spontaneous forgetting” could result from subtle contextual changes. The first experiment demonstrated that when Sprague-Dawley male rats are trained in a runway alley with a food reinforcer, retention performance is dramatically affected by a change in the pattern of the walls of the training apparatus when testing takes place 1, 3, or 5 days following training and not after 1 week. Experiment 2 demonstrated that this performance deficit cannot be alleviated by any of the three selected cuing treatments, whereas “spontaneous forgetting” (resulting from a training-to-test interval of 14 days) can be. These data indicate that the detrimental effect of contextual change reduces over time, and that such an effect cannot be interpreted in terms of retrieval failure. These results lend strong support to the argument that the disruptive contextual change effect is basically different from the disruptive effect that results from an extended training-to-test interval.