TED-Ed: What happens when you remove the hippocampus? - Sam Kean

In 1953, Dr. William Scoville performed a lobotomy on Henry Molaison (H.M.) to treat his seizures, removing his hippocampus. While the surgery reduced seizures, it severely impaired H.M.'s memory, preventing him from forming new long-term memories. Brenda Milner's research on H.M. revealed distinctions between short-term and long-term memory, and between declarative and procedural memory. These findings revolutionized our understanding of memory processes. H.M.'s case became a cornerstone in neuroscience, with his brain extensively studied after his death, contributing significantly to memory research.

What was the primary reason for H.M.'s surgery performed by Dr. Scoville?

• To enhance H.M.'s memory

• To treat H.M.'s seizures

• To improve H.M.'s IQ

• To study brain functions

What was one of the immediate effects of H.M.'s surgery?

• Improved long-term memory

• Increased emotional response

• Loss of ability to form new memories

• Enhanced motor skills

What did Brenda Milner discover about H.M.'s memory capabilities?

• H.M. could remember events from his childhood

• H.M. could form new long-term memories

• H.M. had no memory retention at all

• H.M. could retain information momentarily

Which part of the brain is crucial for memory consolidation, as highlighted by H.M.'s case?

• Frontal lobe

• Hippocampus

• Cerebellum

• Basal ganglia

What type of memory did H.M. retain despite his condition?

• Declarative memory

• Procedural memory

• Episodic memory

• Semantic memory

What experiment demonstrated H.M.'s ability to learn new motor skills?

• Identifying colors

• Reciting a poem

• Solving math problems

• Tracing a star through a mirror

What was the significance of H.M.'s brain preservation after his death?

• To cure his condition

• To improve surgical techniques

• To create a digital map for research

• To enhance his memory