Acquisition and transfer of feature-negative discriminations

This experiment examined the acquisition and transfer of inhibitory stimulus control in serial feature-negative (A+, X→A−) discriminations in a conditioned suppression situation. A variety of visual and auditory stimuli were used as A and X in separate groups of rat subjects. The choice of the stimuli used as X and A substantially affected the rate of acquisition of those discriminations. But in no case did X inhibit conditioned responding to another excitor that was separately paired with the unconditioned stimulus. These results replicated, over a wide range of acquisition rates and performance levels, Holland and Lamarre’s (Learning and Motivation, 1984) observation that the inhibitory stimulus control established to the feature in serial feature-negative discrimination procedures was highly specific to the excitor with which it had been trained.