Sunday, February 3, 2019

Claparede's Pinprick Experiment

In 1911, a French physician and psychologist named Edouard Claparede published his observations of a female amnesiac patient. The woman was suffering from a debilitating form of amnesia that left her incapable of forming new memories. She had suffered localized brain damage that preserved her basic mechanical and reasoning skills, along with most of her older memories. But beyond the duration of a few minutes, the recent past was lost to her—a condition brilliantly captured in the movie Memento, in which a man suffering similar memory loss solves a mystery by furiously scrawling new information on the backs of Polaroids before his memories fade to black.

Claparède's patient would have seemed straight out of a slapstick farce had her condition not been so tragic. Each day the doctor would greet her and run through a series of introductions. If he then left for 15 minutes, she would forget who he was. They'd do the introductions all over again. One day, Claparède decided to vary the routine. He introduced himself to the woman as usual, but when he reached to shake her hand for the first time, he concealed a pin in his palm.

It wasn't friendly, but Claparède was onto something. When he arrived the next day, his patient greeted him with the usual blank welcome—no memory of yesterday's pinprick, no memory of yesterday at all—until Claparède extended his hand. Without being able to explain why, the woman refused to shake. She was incapable of forming new memories, yet she had nevertheless remembered something—a subconscious sense of danger, a remembrance of past trauma. She failed utterly to recognize the face and the voice she'd encountered every day for months. But somehow, buried in her mind, she remembered a threat.


Discover: Fear in the Brain

Experiments on Implicit Memory in a Korsakoff Patient by Clapar ède (1907)
https://www.coursera.org/lecture/introduction-psych/lecture-8-what-is-not-forgotten-14-39-min-lC9MU