Punishment-induced resurgence

The phenomenon of extinction-induced resurgence is well established, but there is comparatively little experimental evidence for punishment-induced resurgence. Punishment-induced resurgence can by tested by contingent shocks following the alternative response. The purpose of Experiment 1 was to test whether low-intensity shocks, that do not decrease rate of reinforcement, result in resurgence. Four rats served as subjects. Rats were exposed to three sequential conditions: (a) variable-interval (VI) 30-s food delivery for a lever press (target response); (b) VI 30-s food delivery for a nose poke (alternative response) and extinction of the lever press; (c) VI 30-s reinforcement for a nose poke with superimposed VI 60-s shock delivery. In the final condition, shocks increased gradually from 0.1 to 0.5 mA. Experiment 2 evaluated whether an abrupt introduction of a high- intensity shock would result in resurgence. Three rats served as subjects and were exposed to three sequential conditions: (a) VI 30-s food delivery for a lever press; (b) VI 30-s food delivery for a nose poke and extinction of the lever press; (c) continued VI 30-s reinforcement for a nose poke with superimposed VI 60-s 0.6 mA shock delivery. Resurgence was observed in all subjects, including in situations in which rate of responding, but not rate of reinforcement, decreased. The present study provides additional evidence for punishment-induced resurgence, but future studies are warranted to determine the extent to which punishment can produce resurgence with or without decreases in rates of reinforcement.