Interactions between the discriminative and aversive properties of punishment.

Punishment acquires a discriminative property when it is selectively paired with either reinforcement or extinction. At the milder punishment intensities, the discriminative control exerted by punishment is similar to the discriminative control exerted by a response-produced neutral (nonaversive) stimulus. However, the effect of the aversive property is apparent as the intensity of the punishment is increased. The aversive property of the punishment acts to enhance the discriminative control when the punishment is selectively applied during extinction periods, and to attenuate the discriminative control when the punishment is selectively applied during reinforcement periods. One major difference was found between the control exerted by the punishment and the response-produced neutral simulus: Responding greatly increased after the S(Delta) punishment but not after the S(Delta) neutral stimulus; this increase in responding was independent of the punishment intensities studied.