GENERALIZATION AND DISCRIMINATION AS A FUNCTION OF THE SD‐SΔ INTENSITY DIFFERENCE1
Three groups of four rats were trained on an auditory-intensity discrimination for 21 days. The SD-SΔ intensity difference for Group I was 10 db; for Group II, 20 db; and for Group III, 30 db. Following the initial discrimination training, the animals were tested for generalization of the bar-press response to seven novel SΔ's which were presented intermingled with the original SD and SΔ values. Conclusions: (1.) The amount of simple discrimination training required to obtain fairly stable differences in SD and SΔ responding is an inverse function of the magnitude of the stimulus difference between SD and SΔ. (2.) Generalization gradients obtained immediately following simple discrimination training exhibit a maximum displaced from SD in a direction also away from SΔ. (3.) Gradients obtained following continued exposure to the multivalued SΔ situation show a fairly stable maximum at the SD value. (4.) Although the gradients tend to fall off systematically on either side of the continuum as distance from SD is increased, they decrease most rapidly on the SΔ limb of the gradient.