Some variables affecting conditioned suppression in humans

Abstract

An attempt was made with 20 adult male human subjects to produce the behavioral disruption demonstrated in animals and called conditioned suppression or the conditioned emotional response (CER). Various intensities of ac and dc electric shock were used, including maximum intensities which would maintain subjects' attendance at sessions. The preaversive stimuli and the shock were imposed upon lever pressing behavior maintained on VI Schedules of reinforcement and on FI-LH schedules. Animal research suggests that these schedules are highly sensitive to the CER effect. Parameters of the preaversive stimulus such as loudness, duration, and average interstimulus interval were selected which maximize the likelihood of obtaining suppressive effects with animals. No conditioned suppression was obtained. Until further clarification of the status of the CER in humans is available, attempts to describe human behavior in terms of “conditioned anxiety”, viewed as analogous to the CER in animals, appears unwarranted.