Could a painful stimulus be effectively used as a learning aid? In rats, the application of a painful stimulus has shown an increase in overall arousal and the ability to learn certain behaviours (The study is neatly summed up in this video: Motivation and Reward in Learning). The experiment with electric shocks is shown on the second half.

It is common sense that human beings would naturally avoid painful consequences, but the deliberate application of a noxious stimulus may also elicit a unconscious response, or conditioning, to avoid those behaviours, which would mean a faster learning rate.

Learning could also be improved because pain is an intrinsically meaningful response, while perceived failure is somewhat weaker and less imediate as a motivating agent.

Could small electric shocks, applied by another individual, or a computer program (maybe even self-administered), have any use in learning? At what specific tasks would this technique be more effective?
Claparede's Pinprick Experiment

From http://www.fearexhibit.org/brain/memory/claparedes_pinprick_experiment:


  In 1911, a French doctor named Edouard Claparede published his
  observations of an amnesiac patient. Despite repeated interactions
  with the woman, sometimes only minutes apart, Claparede had to
  reintroduce himself every time he reentered the room; the patient
  never recognized him as someone she'd met.
  
  During one of their "introductions," Claparede hid a tack in his palm
  and pricked the patient when they shook hands. The next time they
  "met," the patient refused to shake Claparede's hand though she
  couldn't explain why since she did not recall ever having met the
  doctor.
  
  Today, scientists interpret the patient's reaction as proof that
  multiple memory systems are at work within the normal human brain. A
  subconscious memory system in the woman's brain had formed an
  association between shaking Claparede's hand and a painful experience.
  Therefore, despite the dysfunctional state of the memory system that
  would have normally enabled the patient to consciously remember the
  event, another memory system was still working, trying to keep her
  safe from harm.
  
  A century ago, Claparede's observations were not readily understood as
  such evidence for multiple memory systems. We owe much of our
  knowledge about the brain and memory to studies of animals. Without
  these examinations, scientists might never have properly interpreted
  such observations of human subjects.