Examined the effects of atropine in 4 experiments with a total of 10 male squirrel monkeys. Punishment-suppressed operant responding was disinhibited in 2 different experimental paradigms by the administration of atropine to the ventromedial hypothalamus, but many Ss failed to consume the rewards earned during periods of disinhibited responding. Drug treatment also facilitated unpunished operant responding in some situations, but inhibited punished as well as unpunished consummatory behavior. The observed pattern of effects is discussed in relation to earlier reports of the effects of atropine injections or lesions in the ventromedial hypothalamus of rats. (26 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)