No word on what impact Einstein's brain had on his hairstyle.

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Unsolved Mystery: What Sandra Witelson Discovered

Dr. Diamond's work had received tremendous press coverage, only to be exposed as critically flawed in execution. In 1996, a University of Alabama researcher named Britt Anderson published another study on Einstein's brain with much less hullaballoo. Anderson had discovered that Einstein's frontal cortex was much thinner than normal, but that it was more densely packed with neurons [source: Hotz]. Anderson told Thomas Harvey that a researcher at McMaster University in Hamilton, Ontario, had been studying whether a more tightly packed cortex might explain differences in men's and women's brains. While men's brains were bigger, women's brains had the neurons packed tightly together, which may mean they can communicate more quickly.

Harvey took the name of that researcher and sent her a one-line fax: "Would you be willing to collaborate with me on studying the brain of Albert Einstein?" [source: Hotz]. Dr. Sandra Witelson, the researcher at McMaster, answered back in the affirmative. What Witelson had going for her that other researchers did not was a large collection of brains with IQs, general health and psychiatric state accounted for. There would be no confusion about the control group, as there was with Diamond's work -- the 35 male brains used had an average IQ score of 116, slightly higher than normal (Witelson used 56 female brains for comparison as well). For decades, Witelson had been working with doctors and nurses to acquire brains for her research. She would be able to conduct the largest study of this kind.

Harvey went to Canada with the brain, and Witelson was allowed to select nearly a fifth of it for study -- more than any other researcher had been allowed before [source: Altman]. She selected pieces of the temporal and parietal lobes, and she also pored over the photographs Harvey had commissioned of the brain at the time of Einstein's death. She noticed that Einstein's Sylvian fissure was largely absent. The Sylvian fissure separates the parietal lobe into two distinct compartments, and without this dividing line, Einstein's parietal lobe was 15 percent wider than the average brain [source: Witelson et al.].

Significantly, the parietal lobe is responsible for skills such as mathematical ability, spatial reasoning and three-dimensional visualization. This seemed to fit in perfectly with how Einstein described his own thought process: "Words do not seem to play any roles," he once said. "[There are] more or less clear images" [source: Wilson]. The man who figured out the theory of relativity by imagining a ride on a light beam through space saw his ideas in pictures and then found the language to describe them [source: Lemonick].

Witelson hypothesizes that the lack of a Sylvian fissure may have allowed the brain cells to crowd in closer to one another, which in turn enabled them to communicate much faster than normal. This brain structure may also have had something to do with Einstein's delayed speech development, which raises questions about whether it's helpful to know this sort of information about yourself. If Einstein had known that his brain was different, maybe even flawed, would he have pursued academics?

At this point, scientists don't know enough about how the brain works to know if Witelson's work is accurate, though it's the going theory at the moment. For all visible purposes, Einstein's brain seems perfectly normal, if not a little damaged, with nothing that would immediately indicate any great genius. We may not know anything until there's another equivalent genius brain to study; perhaps Einstein can't be compared to average brains.

Harvey never gave up on his belief that the brain would reveal something special. Near the end of his life, after carting the brain around the country, he returned to the place from which he had taken it: Princeton Hospital. He gave the brain to the man who had his old pathology job; writer Michael Paterniti, who accompanied Harvey on one cross-country trip with the brain, hypothesized in the book "Driving With Mr. Albert" that Harvey picked someone who represented a sort of reincarnation of Harvey himself, something that the pathologist in question also acknowledges. "Well then, he's free now," the man told Paterniti of Harvey's choice, "and I'm shackled" [source: Paterniti]. If Einstein's brain ever truly reveals its secrets, Harvey won't be here to see it; he died in 2007 at the age of 94. Einstein and the mystery of his brain, however, live on.

For many more answers to questions about the brain you never thought to ask, see the links to articles on the next page.