Knowledge Of Brain, Memory Came From ‘TM’

In neuroscience, “HM” was a superstar of brain research.

This man, who had suffered from epileptic seizures since he was a teenager, was 27 when surgeons took a radical approach to treat his malady. In 1953 they operated and removed his brain’s anterior temporal lobe, including most of the amygdala and the hippocampus on both sides, according to an online story by PBS.

http://www.pbs.org/newshour/rundown/2013/02/post-24.html

Neuroscience students know all about HM, whose identity for years wasn’t disclosed. But he died in 2008, and now his name has been revealed: Henry Gustav Molaison.

PBS did a story Monday about a panel on Molaison that was conducted last week at the American Association for the Advancement of Science meeting in Boston. The panelists were researchers who had actually studied Molaison before his death and after, according to PBS.

When the large piece of Molaison’s brain was removed, he no longer had short-term memory.

“He could remember facts about his life before the surgery … And he could converse easily with a new person,” PBS wrote. “But if that new person left the room for five minutes or 10 minutes and returned, he would have no recollection of the interaction.”

One of the panelists, Brenda Milner of the Montreal Neurological Institute and Hospital, said that she studied Molaison for three decades and her never learned her name, according to PBS.

An MIT researcher, Suzanne Corcoran, said Molaison’s case proved that the hippocampus and the cortex were crucial to memory, PBS reported. And another takeaway was that even though Molaison had amnesia, he was intelligent with an above-average IQ. He was described as friendly and happy, and pleased to be studied and to therefore advance science.

Panelist Howard Eichenbaum of Boston University, according to PBS, said that the brain creates memories using “place cells” and “time cells,” different kinds of neurons in the hippocampus.

Place cells fire when an animal is in a specific location, while time cells fire at specific moments in time, PBS reported. The two complement each other to form a memory, according to Eichenbaum.