So much of what we know about the brain comes from patients who have brain damage; we only understand a piece’s function once it is missing. Thus, the outliers make the rules, which is counterintuitive to the basic nature of science, and I think that’s fascinating.
The book Phantoms in the Brain talks about this, using different examples of people who are missing certain parts of their brain to boost our understanding of the brain as a whole. The most famous example is that of phantom limbs, and how the brain’s plasticity allows it to be re-wired by simple visual repetition. Buy the book & read it, you’ll love it.
Perhaps the most famous example is Patient HM, named Henry Molaison, who had experimental surgery to remove his hippocampus when he was 27. The thought was that this surgery would cause a stop to his chronic epileptic seizures, which was indeed the case. However, it also caused him to suffer from severe anterograde amnesia – the ability to form new memories after brain damage occurred.
Thus, for the last 55 years of his life, Henry was poked, prodded, and studied at length and in depth by a myriad of researchers. He was one of a kind: A man who could form no new memories. Repeated experiments showed that was unable to form new long-term memories, but he could remember events that occurred before the surgery. Also, he could learn new motor skills (though he would not necessarily remember the process by which they were learned) and he could draw a map of the house he lived in, even though he hadn’t moved in until 5 years after his amnesia-inducing operation.
These seemingly-counterintuitive observations of Henry’s memory completely reshaped our theory of memory formation. Now that Henry has died, his brain sits in 2401 slices so that it may be studied and imaged on the most microscopic level.
1. Early science is fascinating. HM’s surgeon decided to take out both sides of his hippocampus if only because he was an experimental surgeon in the 1950s. If you were a doctor who cut out part of a patient’s brain willy-nilly, you would probably get a royalty check from CNN for the 24 hours of outrage-generated ad revenue. But you could do stuff like that in the 50s, if only because nobody was aware of the mind’s intricate complexity, and the only way to discover said complexity was through this radical, accidental experimentation. Kind of a catch-22.
2. A great quote from the last article (which is 300 times better than this post):
Brain surgery, whatever the era, always requires at least two frightening qualities in its practitioners: the will to make forcible entry into another man’s skull, and the hubris to believe you can fix the problems inside.
Dr. Scoville (Henry’s surgeon), and any experimental surgeon for that matter, had enough hubris to power a battleship. I love it.