What did you eat for lunch? Who won the last presidential elections? What are the latest coronavirus measurements in the world? Our everyday life is full of new faces, news, and significant and minor events. Some of them you wish to keep with you forever, traveling back and forth in your mind. Some, probably as of 2020, you wish to erase without even a hint of its existence. Our modern understanding of how memory is formed and organized would not be possible if one man would not have given his memories to science.
H.M. patient, how he is usually called in the scientific community, or Henry Gustav Molaison had been knocked down by a bicycle in childhood. As a result, he received a brain injury which leads to severe seizures. Being bullied at high school he was forced to change schools and graduate at the age of 21. He worked at a few places repairing car motors, but by the age of 27, his seizures reached a critical point. It was dangerous to be away from home. Treatment with high doses of anti-epileptic drugs didn’t work out. The last solution was to physically remove the localization of seizures in the brain, but doctors were not able to find “the hot spot”.
Doctor Scoville offered Henry a “frankly experimental operation”. He removed sections of the medial brain structures, the hippocampus, and the surrounding cortex, on both sides of the brain. The seizures went away, however, the consequences made a breakthrough in understanding how memory works. His brain was not anymore able to form new conscious memories. He could remember his parents’ names, facts from his childhood, famous people, and events that occurred before the operation. Yet time stopped for him in 1958. So, what did the world learn from this guy?
Memories are not distributed throughout the whole brain
Before the H.M. surgery, the scientists believed that all the neurons work together in the brain to evoke a memory. In Henry`s case, he kept memories from his youth and was still able to form new procedural memories (how to play piano or ride a bicycle) but his ability to form new declarative memories (like what he ate for lunch, someone`s name, what was in the TV show which he had just watched) was lost. This showed us that different types of memories are localized in specific regions and not stored throughout the whole brain.
Intellect and perception are distinct cognitive functions
Even though he experienced every aspect of his daily life as it first described his state as “like waking from a dream … every day is alone in itself…”, his intellect, personality, and perception stayed intact. It was believed that memory function was strongly integrated with intellectual and perceptual functions. Surprisingly, this finding indicated that memory is a separated cognitive mechanism, which was a huge push for a modern cognitive science.
Fearlessness and a sense of humor help you if the situation seems unexplainable
It is hard to imagine what a person, forever stuck at the age of 27, could feel when he sees a gray haired man covered with wrinkles in the mirror.How is it to not have control and to not be aware of the changes of this fast world? How does it feel not to know what just happened to you and who are those people who ask you to pass one test after another? After being studied for 50 years, researchers who worked with Henry remembered him as a person who kept his sense of humor throughout his life. He welcomed the world and people in it with fearlessness and an open heart until his very last days. He showed us that in the majority of the situations, a good joke and a brave heart was enough to welcome a new unexpected day. Henry Gustav Molaison passed away in 2008, at age 82, started a revolution in research that he was unaware of.