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What happens when you remove the hippocampus? - Sam Kean

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When Henry Molaison (now widely known as H.M.) cracked his skull in an accident, he began blacking out and having seizures. In an attempt to cure him, daredevil surgeon Dr. William Skoville removed H.M.'s hippocampus. Luckily, the seizures did go away — but so did his long-term memory! Sam Kean walks us through this astonishing medical case, detailing everything H.M. taught us about the brain and memory.

Brenda Milner’s observations and discoveries helped with two types of memory, a distinction between knowing “that” and knowing “how.” This has been a major basis for most memory research since then. Explain what this means. Why is this idea so important?

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About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Sam Kean
  • Director Anton Bogaty
  • Narrator Addison Anderson

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