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Fear & the Brain

Claparede's 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.