Instrumental learning within the spinal cord: IV. Induction and retention of the behavioral deficit observed after noncontingent shock.

Spinalized rats given shock whenever 1 hind leg is extended learn to maintain that leg in a flexed position, a simple form of instrumental learning. Rats given shock independent of leg position do not exhibit an increase in flexion duration. Experiment 1 showed that 6 min of intermittent legshock can produce this deficit. Intermittent tailshock undermines learning (Experiments 2-3), and this effect lasts at least 2 days (Experiment 4). Exposure to continuous shock did not induce a deficit (Experiment 5) but did induce antinociception (Experiment 6). Intermittent shock did not induce antinociception (Experiment 6). Experiment 7 addressed an alternative interpretation of the results, and Experiment 8 showed that presenting a continuous tailshock while intermittent legshock is applied can prevent the deficit.