HEART-RATE LEARNING IN NONCURARIZED STATE, TRANSFER TO CURARIZED STATE, AND SUBSEQUENT RETRAINING IN NONCURARIZED STATE

One group of freely-moving rats was trained to increase, and another to decrease, heart rate in order to avoid and/or escape electric shock. This training produced a statistically reliable difference between the groups. This difference persisted when the rats subsequently were tested and then given additional training while paralyzed with curare and maintained on artificial respiration. The same difference also persisted during subsequent nonreinforced tests without curare and was further increased by additional reinforced training in the normal, free-moving state. During the initial session of noncurarized training, the group rewarded for increases in heart rate showed more activity than the one rewarded for decreases, but there were no reliable differences in respiration rate. At the end of the second session of noncurarized training, the difference between the groups did not approach statistical reliability in activity (t=0.7), respiration rate (t=0.2), or the variability of that rate (t=0.6), but was highly reliable in heart-rate (t=7.2, df=12, p<0.001). © 1969.