November 16, 2012 | 23
Ever since his death in 1955, scientists have asked what features of Einstein’s brain contributed to his extraordinary insights into physical laws.
Research on the anatomy of Einsteins’ genius was stymied because many of the post-mortem images and slides of tissue from the subsequently dissected organ were unavailable to researchers. The story is complex and the fate of Einstein’s brain, in fact, has furnished sufficient anecdotal raw material to produce a number of popular books.
In addition to the human drama, scientists have in recent years identified a few special attributes. The size and structure of Einstein’s parietal lobes, involved with processing spatial relationships and numbers, seemed tied to his mathematical ability.
Now a new study in Brain, based on the most comprehensive collection of post-mortem images compiled to date, shows that Einstein’s cerebral cortex, responsible for higher-level mental processes, differs much more dramatically than previously thought from that of your Everyman of average intelligence. The paper, in fact, publishes for the first time the “road map” to the father of relativity’s brain, photographs that image 240 blocks of dissected tissue from the autopsy performed at the University of Pennsylvania by Thomas Harvey.
An edited interview follows with noted anthropologist and lead researcher Dean Falk of Florida State University.
What did you find in the study?
Although Einstein’s brain was of a normal size and it’s overall lopsided shape was normal for a right-handed male, the pattern of convolutions on the outside surface of the cerebral cortex was very complex in specific regions of different lobes of the brain.
Why are these convolutions important?
The cerebral cortex, the outside part of the brain, is really important because it’s where we humans do our higher conscious thinking. It’s the most advanced region of the brain. As our ancestors’ brains increased in size, there was a tendency for more convolutions to appear in the cortex. The convolutions are a way of increasing volume in the brain in a closed container like the skull. The convolutions are also important because they may be indicative of the extent of connections beneath the brain’s surface. In some cases, the grooves that delimit the convolutions , the sulci, may even define a specific functional area.
Did the particular convolutions in Einstein’s brain give any clues as to what his special cognitive gifts might have been?
We compared his brain to descriptions in the literature of the cerebral cortex of 85 normal brains. At times we were able to make reasoned speculations. For instance, Einstein had extraordinary prefrontal cortices, right behind the forehead, which revealed an intricate pattern of convolutions.
We know from comparative studies in primates that this part of the brain became highly specialized during hominin evolution. We also know that in humans that this area functions in higher cognition that entails working memory, making plans, bringing plans to fruition, worrying, thinking about the future and imagining scenarios. It is an extraordinarily evolved part of the brain that is related to connections between neurons underneath the surface of the brain. We’re hypothesizing that what we’re seeing in Einstein’s brain is a lot of complexity in these connections.
Why has it taken over 50 years to get to this point?
There’s only been a handful of studies and there were only a few photographs included in those studies. I knew there should have been lots of other photographs, but I couldn’t get my hands on them. I tried, but until recently doors slammed shut. So it was very frustrating. What had happened was that after the brain was harvested, slides and photographs were given out to a few scientists but many were for all practical purposes lost. In fact, much of the material is still unaccounted for.
Fred Lepore [of Robert Wood Johnson Medical School] decided to try to find the missing photographs, which led him to the family of the pathologist [Harvey] who harvested the brain. As it turned out, the family had a treasure trove of material, which they have generously donated to the National Museum of Health and Medicine. This fulfills a goal of Harvey himself as well as the wishes of the Einstein family.
Haven’t there been previous studies looking at Einstein’s brain and finding features that looked interesting?
Other studies looked at very limited parts of the cerebral cortex and found some features that were remarkable. What we’ve done is look at the entire cerebral cortex and identify features that are extraordinary in numerous parts of the brain. For example one of our findings was that segments of the parietal lobes were highly asymmetrical. Sandra Witelson’s earlier study of Einstein’s brain correctly noted that parietal lobes are important for mathematical and visuospatial abilities, which has since been confirmed in functional imaging studies.
Einstein’s parietal lobe asymmetries are striking. I tried to find something in the literature that could explain the great size of the right superior parietal lobule [a segment of the parietal lobe] and illuminate what it does differently than its left counterpart. Although there are a few suggestive reports, I don’t think the literature is there yet. I’d like to know about the different functions of this region on the two sides of the brain in normal people. It may be that the striking parietal lobe asymmetries in Einstein’s brain are related to his extraordinary mathematical and visuospatial thinking, as Witelson [at McMaster University] and her colleagues suggested.
You’re a leading anthropologist who has done a lot of noted work on Hobbit fossils. What got you interested in Einstein’s brain?
I’m interested in hominin brain evolution so I’m stuck with the external cerebral cortex because you get fossil evidence for that, but nothing internal. You can’t do research on hominin brain evolution without studying the cerebral cortices of living primates and people. I became interested in Einstein’s cerebral cortex because published studies from the functional brain imaging literature suggested to me that a particular bump in Einstein’s right frontal lobe was related to his intensive musical training on the violin when he was a child.
That got me very interested in Einstein’s brain and wanting to see the rest of it. Once we finally obtained the missing photographs, I realized that we could see and, therefore, describe the entire cerebral cortex, which is what this paper is about. It took a long time to identify all of the grooves and convolutions because I had to visually rotate between different views of Einstein’s brain to make sure that my identifications were consistent from view to view. Some people are gifted in visuospatial rotations but I am not, so it was hard work.
Were there other things that were also unusual?
One of the most interesting things about Einstein’s brain has to do with his sensory and motor cortices. We found an unusual region lower down in the motor cortex that processes information from the face and tongue and laryngeal apparatus. The motor face area in Einstein’s left hemisphere was extraordinarily expanded into a big rectangular patch that I’ve not seen in any other brain. I am not sure how to interpret this. In a famous quotation, Einstein wrote that his thinking entailed an association of images and ‘feelings’, and that, for him, the elements of thought were, not only visual, but also ‘muscular’ What does that mean? I don’t know, but in light of what we found in the motor cortex it’s a very interesting quotation.
Do you think this has anything to do with that famous photo of Einstein sticking his tongue out?
I’ve been asked that four times in the last three days. The first time the question caught me by surprise and I said I thought it was just a coincidence. Then I got to thinking about it and went to a mirror to see whether I could get my tongue out as far as Einstein had, and I came pretty close. So I think that wonderful photograph was probably Einstein just being spontaneous and impetuous.
What are next steps in your research?
It took months of intensive study to describe Einstein’s cerebral cortex. I was staring at the ceiling at night and seeing sulcal patterns. My hope is that others will find our description of Einstein’s external brain useful when they study the newly emerged [tissue] slides and when they look at brains from other people, including geniuses. Right now, I have fossil projects waiting that I want to get back to.
Image Source: Ferdinand Schmutzer