Chained schedules of avoidance: Reinforcement within and by avoidance situations.

Four rats were exposed to chained schedules with variable-cycle avoidance in both links. Responding in the initial link cancelled shocks scheduled once per minute and, according to a conjoint fixed-ratio schedule, produced a terminal link where scheduled shock rates varied from 0 to 8 shocks per minute in different conditions of the experiment. Response rates in the terminal link increased as a function of the scheduled shock rate. Response rates in the initial link, on the other hand, decreased as a function of the shock rate actually received (rather than scheduled) in the terminal link. While consistent with other studies of aversive control, these results differ from those obtained in chained schedules of positive reinforcement in that increases in reinforcement within the terminal link of the chain did not systematically increase the reinforcing value of that link.