Henry Molaison was the man without memory
An article about the most famous patient of neuroscience.
The night Henry Molaison died
The night Henry Molaison (en.wikipedia.org/wiki/Henry_Molaison) died, there was no time for mourning.
When Ph.D. Suzanne Corkin (head of the Corkin Lab, Professor of Behavioral Neuroscience, Principal Investigator at MIT) learned that Henry had died, she did not think about his mesmerizing smile. Or the many hours she spent with him in the laboratory. Presently, all Suzanne Corkin cared about was his brain.
In nearly 40 years, Suzanne has investigated many patients. Dementia, brain surgery, brain injuries. But none was like Henry Molaison. Over centuries, Suzanne Corkin has talked to him and followed his fate – or doom.
A considerable part of her success as a scientist results from this case study. Her tests and examinations made Henry the best-studied neurology patient.
Therefore, when Suzanne Corkin heard the news, she knew that it was time to act. She called Henry's legal guardian and asked for the permission to remove his brain.
Corkin rushed to the Martino Center for Biomedical Imaging, where she directed the hearse onto the ramp in front of the building.
For nine hours, the scientists scanned Henry's brain in the MRI scanner. Corkin was aware of the importance of this historical moment. During the autopsy, she made sure not to miss a moment. Then finally, 2 pounds (0.91 kg) of nerve tissue were lying in front of her in a metallic shell.
“It was the most satisfying moment of my life”, Suzanne Corkin explained in a recently published report. (Source: “Permanent Present Tense – The Unforgettable Life of the Amnesic Patient, H.”)
4.5 years later, Scientists are ready to present the results
Meanwhile, scientists in California are working on piecing the 2401 slices the brain was cut into back together.
In 1953 at the age of 27 a doctor, William Beecher Scoville, removed both of Henry's hippocampus. Henry Molaison was suffering from severe epileptic seizures.
The desired effect was there. Since then, Henry Molaison rarely suffered from epileptic seizures. But only a few days after the surgery, doctors realized that they made a huge mistake. And that something went terribly wrong.
The patient had lost his sense of direction. He could not remember the faces of the nurses and could not memorize medical instructions. He could not even remember why he was in that hospital.
The surgery has robbed him of an elemental ability: His memory. Or should I say: One of his forms of memory? From then on, Henry Molaison was doomed to live in the presence. Cut off from future and past. An island of constant present tense.
Scoville admitted that the surgery was a tragic mistake, and the amputation of both hippocampus since then is a taboo.
But that was only the first of many lessons scientists learned from the patient Henry Molaison.
The beginning of Neuroscience
Back then, neuroscience did not yet exist. Scientists only had vague knowledge of the functions of the brain centers and how the memory works.
Surgery for mental conditions was common, but it was more like risky shredding in the dark, really.
Since then, scientists have gained vast knowledge, and the patient Henry Molaison has a substantial part in that.
Over the centuries, Henry Molaison visited the MIT laboratory 55 times. 122 scientists researched what he was able to do—and what not.
They made him smell, feel, draw and count. He had to memorize numbers, play computer games and discover mazes.
He was eager and patient. Likewise, he could not remember that he failed the task hundreds before.
The tragic fate of the man without memory first drew the attention of scientists to the hippocampus. It was proven that only when sensory impressions get routed through them, they can be memorized.
Scientists discovered that without the hippocampus, a sensory impression fades and vanishes after 30 seconds.
Sometimes H. M. was able to trick the scientists by being able to recite number sequences. But only because he had continuously repeated them in his brain. A few moments of distraction and they were lost forever, and H. M. could not even remember that he wanted to memorize a number sequence.
There are different types of memory
Not only the clear distinction we make today between short-term and long-term memory is owed to H.M. The central observation was: There is more than one type of memory.
Scientists were aware that they had a long road to go ahead of them.
H.M. failed all memory tests and always greeted the scientists as strangers. But every time he seemed to understand faster what the scientists asked from him. It was as if he became used to the test procedures.
Isn't that a hidden form of memory?
Hundreds of tests and experiments helped Corkin and her colleagues to understand what H.M. could memorize.
The power of the subconsciousness
Obviously, what H.M. learned unconsciously helped him to handle the presence. H.M.´s world was scary. Every morning, he woke up in a room he did not know that was equipped with items he did not know. Surrounded by strangers.
After all, his last memory was from the fifties. From before the surgery.
But Henry was not scared. He reacted with friendly patience to the strange world around him. His subconscious was familiar with it.
Not even the reflection of his face in the mirror scared him. Even though, when asked for his age, his answer was decades off. Even though when asked he said his hair color is brown. But his reflection in the mirror was that of an old, gray-haired man.
After all, he knew this person very well – just his conscious mind was not aware of it.
Henry was fully aware of the time before the surgery. He enjoyed talking about his childhood. He knew every politician of the 50ties.
When scientists continued to ask him questions, they made another discovery: This part of his memory was damaged too.
Even though he could still recite the facts after the surgery, all life has vanished from the memories. Henry could recall where he went on vacation with his family. What they did. But not the emotions he had felt.
Henry was missing what today is known as “episodic memory”. He was left with the semantic memory. The distinction between episodic and semantic memory is also owed to H.M.
Scientists believed that the surgery did not delete Henry's memory. Their conclusion was that the memories just were not available to his conscious mind.
Just like data that is stored on a disk but cannot be searched for as it vanished from the index. Somewhere in Henry's brain, the romance with this first love or his bike accident have left traces. But where?
Scientists hoped to find answers to this and other questions by reconstructing Henry's brain on the computer.
Why was Henry's sense of smelling damaged after the surgery? How could he realize when a strong scent hit his nose without being able to tell if it came from rotten fish or roses?
Why did Henry lose any sense of feeling full? When scientists after a meal gave him another portion, he ate it without complaining.
You can read the full story of Henry Molaison HERE
Conclusion
- Our subconscious has a major impact on us, our behavior, and finally, our success.
- Memories we cannot consciously recall impact us in a big way.
- The brain can be trained and retrained.
- Success blockers are hidden in our subconscious.
Other articles from this miniseries:
Neuroscience and Weight Loss
Neuroscience and Fear
