Generalization of extinction of an instrumental response with circle size as the stimulus dimension

Thesis (Ph.D.)--Boston University.Gradients of extinction were determined for an instrumental response, with circle size as the stimulus dimension. The Ss were 69 albino rats. All animals were given equal training in a runway to each of three stimuli, consisting of metal disks painted white and having areas of 20 cm2 , 40 cm2, and 79 cm2, respectively. After the training series of 30 trials, 27 animals were given 10 extinction trials to the 20-om2 circle, and 30 animals, to the 79-om2 circle. Each animal was then given a test-extinction series of 20 trials to one of the three stimuli, with approximately equal groups assigned to each stimulus. A control group of 12 animals was given both preliminary and test-extinction series to the 40-om2 circle [TRUNCATED]