Spontaneous recovery varies inversely with the training-extinction interval

Four experiments found the magnitude of spontaneous recovery after extinction to be greater with a shorter interval between initial conditioning and extinction. Experiments 1 and 2 used a Pavlovian magazine approach procedure with rat subjects, Experiment 3 used an instrumental training procedure with rats, and Experiment 4 used a sign-tracking procedure with pigeons. These results are not anticipated by many accounts of spontaneous recovery that attribute it to the fading of learning that occurred during extinction.