Conditioned approach: an analogue of conditioned avoidance; effects of chlorpromazine and diazepam.

An analogue of the conditioned avoidance test, the conditioned approach test, was designed in which the reinforcing event was eating food rather than avoiding or escaping shock. A response to the approach stimulus resulted in immediate delivery of food. Failure to respond to the approach stimulus for 15 sec resulted in the delivery of a food pellet. Administration of chlorpormazine at 2--4 mg/kg, PO to squirrel monkeys resulted in the failure of the monkeys to respond to many approach stimuli although they promptly responded to the freely delivered food pellet. Diazepam was without effect at doses up to 100 mg/kg, PO.