If the space program teaches us anything about electroshock conditioning, it’s that a strong mind can get past it. Enos, a 39-pound chimpanzee, was trained with the technique to run through the routine he’d need to complete the first primate orbiting of the Earth. During months of training, if he pulled a switch or lever out of succession, he received a mild electric shock. If he pulled the correct one, he received a food pellet reward. Trouble was, when he finally went up on his mission in 1961, the system got fouled up. While in space, he was punished for correct answers! They clearly underestimated Enos as he bravely stuck to his guns and forged ahead successfully with his mission despite having to endure 79 punishing shocks.
from Space.com