Mechanisms of inhibitory discriminative control

Rats were trained to discriminate between trials signaled by a tone, during which leverpressing was reinforced with food, and trials signaled by the tone in compound with a light stimulus, during which no reinforcers were delivered. A subsequent transfer test suggested that the light had acquired the ability to suppress operant responding; there was no evidence that this suppression could be attributed to Pavlovian inhibitory conditioning. It is argued that these data cannot be accommodated by current accounts of discriminative control.