Scientists Create a Digitized Version of the Most Famous Brain in Neuroscience History

Henry Molaison is known to have to most famous brain in the history of neuroscience simply because of contribution and bravery as a surgical patient. On August 25, 1953, he underwent brain surgery to treat his chronic epileptic seizures. Today, he is honored for allowing scientists to study his brain and unearth various neuroscience breakthroughs, most notably through the conception of a 3-D model of his brain.

William Beecher Scoville was the Hartford Hospital Neurosurgeon who performed the surgery on Molaison in 1953. Scoville determined where Molaison's seizures originated and removed a fist-sized chunk of brain tissue in parts of both his left and right medial temporal lobes. After the surgery, Molaison's epilepsy was cured for the most part; but since Scoville removed the "hippocampus" - a component that was previously believed to play an important role in short-term and long-term memory - Molaison was unable to create memories, let alone recall any previous memories, of events, names, people, places, or experiences. From the point on, he was literally living in the present moment for the rest of his life.

As a result of the surgery and studying Molaison's brain, neuroscientists were able to make important discoveries about neurosurgery as well as memory formation following the unfortunate outcome.

When Molaison died in 2008, his brain was frozen in gelatin and cut into 2,401 extremely thin slices for further research. The slices were used to create a microscopic 3D model of his brain. What researchers and neuroscientists discovered was the distinction between procedural memory - "the unconscious memory that allows us to perform motor activities" - and explicit memory - "the type of memory that allows us to consciously remember experience and pieces of new information." Both definitions of these terms can be found in this Smithsonian Magazine article.

After these discoveries, it was realized that the hippocampus was largely responsible for encoding long-term explicit memories, but it wasn't entirely necessary for short-term or procedural memory.

Known as "Patient H.M.", Henry Molaison will always be remembered in the world of neuroscience for his brave contributions as a surgical patient.

To read more about this, visit the previously mentioned Smithsonian Magazine article.