Henry Molaison was an American memory disorder patient, known to the medical world as the most important patient in the history of neuroscience. After a surgery for epilepsy, he suffered a rare disorder that made him unable to form new memories. His case helped neurologists in understanding the functioning of the human mind. Born and raised in Manchester, Connecticut, Henry had a bicycle accident when he was 7 years old, after which he started getting epilepsy attacks. By the age of 27, his seizures became so frequent that he became unable to lead a normal life. Hence, he received treatment from Dr. William Scoville, who then performed a surgery. The surgery was partially successful in controlling these seizures, but he developed anterograde amnesia. This meant that while most of his memories prior to the surgery remained intact, his brain could not form new memories. Following this, he lived in a care institute in Connecticut as several tests and researches were performed on him. He played a huge role in establishing a link between memory and brain functions. It led to the development of a new branch of neuroscience, known as cognitive neuropsychology.
Childhood & Early Life
Henry Gustav Molaison was born on February 26, 1926, in Manchester, Connecticut, US. When he was 7 years old, he met with a bicycle accident, which caused trauma to his head. Following this, he began suffering from epilepsy fits. It was still unclear whether the trauma to the head was the only cause of his epilepsy.
Thinking of it as a minor accident, Henry tried living a normal life. Soon, the number of fits increased to about 10 a day. At first, he tried to manage them through medication, but that was good until the medicine was taken in moderate doses. Over time, the intensity and the frequency of the fits increased. Soon, Henry was put on much higher doses.
He somehow finished high school. By his mid-20s, he was trying his best to lead a normal life, working in a motor factory as an assembler. However, the fits refused to stop and began affecting his work performance. Soon, he decided he would get rid of his condition completely.
He went to William Scoville, a neurosurgeon at a nearby hospital. The surgical procedure for curing epilepsy involved removal of both the temporal lobes and hippocampi from the cerebral cortex.
Although this kind of surgery has become common over time, it was a big and risky surgery at that time, as doctors did not have access to advanced imaging tools and equipment to carry out such an intricate procedure. William extensively talked with Henry and his parents about going ahead with the surgery and explained the risks involved.
Henry gave a go-ahead for the surgery, and it was performed on September 1, 1953. Henry’s hippocampi seemed to be totally non-functioning. However, the surgery for controlling epilepsy was deemed successful.
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Life Post Surgery
As a result, Henry Molaison woke up as an amnesiac. Although he remembered events from his childhood and most of his teenage years, such as the market crash of 1929, his memories of a period of 11 years leading to the surgery were severely affected.
He was diagnosed with severe anterograde amnesia, a brain disorder in which a person becomes unable to form new memories. Henry described this new condition as “waking from a dream… every day is alone in itself.”
His condition was a direct result of the surgery that was performed on Henry, and Doctor William Scoville knew that it was not the first case. He got in touch with researchers at 'McGill University’ in Montreal, where two similar cases had been reported. A psychologist from ‘McGill University,’ named Brenda Miller, visited Hartford to observe Henry in person.
She carefully studied his condition, his memories, and his brain functions. What made Henry a perfect subject for further research was the fact that although his amnesia was severe, he was completely healthy otherwise. Henry was also willing to undergo further experiments.
Although his testing began in 1953, which was soon after the surgery, the first official paper on his condition was published in 1957. It was titled ‘Patient HM.’ Brenda used the pseudonym “HM” to protect Henry’s identity. The paper, published by Brenda, became one of the most cited papers in the field of neuroscience.
Before the surgery was carried out on Henry, it was assumed that memory functions are spread throughout the human brain. However, it was proven through Henry’s case that the temporal lobe has the greatest function when it comes to forming or retaining memories.
However, there were arguments regarding which part of the temporal lobe was most responsible, as the surgery had affected many parts within the lobe, such as the hippocampi, the amygdalae, and the entorhinal cortices. It took a few more decades and many further tests on other subjects in order to identify the connection between memories and the temporal lobe.
What also intrigued researchers was the fact that even though he never formed new memories, Henry was able to learn motor skills, without being conscious about them. This further proved that memories had no connection with one’s ability to learn new things. It also proved that the human brain has multiple memory systems. This became one of the greatest breakthroughs in medical history.
Henry Molaison gave clear consent to go ahead with the experiments that were being performed on him. He stayed in Windsor Locks, Connecticut, where the research was conducted. In a way, he dedicated his entire life to research and was thus part of a milestone in the history of neuroscience.
In 1992, he allowed researchers to use his brain for further research following his death. Until the final years of his life, Henry led a relatively normal life. He ate meals every day, took walks, and learned new motor skills. He passed away on December 2, 2008, in Windsor Locks, Connecticut.
Following his death, his brain was scanned deeply through an ‘MRI.’ The ‘Brain Observatory’ at the ‘University of California, San Diego’ acquired it. Scientists at the university studied 2,401 slices of Henry’s brain to observe each part in detail for further information about the connections between the brain and memory functions.
Henry is still remembered as a generous man who had dedicated his entire life to medical science. The research conducted on him has helped save millions of lives.