Effects of REM sleep deprivation on responding under multiple schedules of free-operant avoidance

Abstract

The effects of REM sleep deprivation on free-operant avoidance in rats was examined. Six rats were taught to press a lever to postpone shock for a fixed period of time after each response (response-shock [RS] interval). If they failed to press the lever, shocks were delivered after a fixed period of time (shock-shock [SS] interval). The subjects were exposed to a multiple schedule of reinforcement in which RS intervals were varied, but SS intervals were held constant. For each animal, baselines were established in which the length of the RS interval was inversely related to response rate. The subjects were then repeatedly exposed to 24, 48, or 96 h of REM sleep deprivation under identical tank control and cage control conditions. Compared with baseline and control conditions, REM sleep deprivation increased response rates. Increases in response rates were primarily accounted for by increases in brief interresponse times. The percentage of avoided shocks was not significantly altered across conditions.