Autopsy[edit]
Harvey had reported that Einstein had no parietal operculum in either hemisphere,[9] but this finding has been disputed.[10] Photographs of the brain show an enlarged Sylvian fissure. In 1999, further analysis by a team at McMaster University in Hamilton, Ontario revealed that his parietal operculum region in the inferior frontal gyrus in the frontal lobe of the brain was vacant. Also absent was part of a bordering region called the lateral sulcus (Sylvian fissure). Researchers at McMaster University speculated that the vacancy may have enabled neurons in this part of his brain to communicate better. "This unusual brain anatomy...[missing part of the Sylvian fissure]... may explain why Einstein thought the way he did," said Professor Sandra Witelson who led the research published in The Lancet. This study was based on photographs of the whole brain made at autopsy in 1955 by Harvey, and not direct examination of the brain. Einstein himself claimed that he thought visually rather than verbally. Professor Laurie Hall of Cambridge University commenting on the study, said, "To say there is a definite link is one bridge too far, at the moment. So far the case isn't proven. But magnetic resonance and other new technologies are allowing us to start to probe those very questions."[11]
Glial cells[edit]
In the 1980s, University of California, Berkeley professor Marian C. Diamond persuaded Thomas Harvey to give her samples of Einstein's brain. She compared the ratio of glial cells in Einstein's brain with that of the preserved brains of 11 other people. (Glial cells provide support and nutrition in the brain, form myelin, and participate in signal transmission, and are the other integral component of the brain, beside the neurons.) Dr. Diamond's laboratory made thin sections of Einstein's brain, each 6 micrometers thick. They then used a microscope to count the cells. Einstein's brain had more glial cells relative to neurons in all areas studied, but only in the left inferior parietal area was the difference statistically significant. This area is part of the association cortex, regions of the brain responsible for incorporating and synthesizing information from multiple other brain regions.
The limitation that Diamond admits in her study is that she had only one Einstein to compare with 11 non-genius brains. S. S. Kantha of the Osaka Bioscience Institute criticized Diamond's study, as did Terence Hines of Pace University.[2] Other issues related to Diamond's study point out glial cells continue dividing as a person ages and although Einstein's brain was 76, it was compared to brains that averaged 64 in age. Additionally, there is little or no information regarding the samples of brains that Einstein's brain was compared against such as IQ score, neurological diseases or other relevant factors. Diamond also admitted that research disproving the study was omitted. His brain is now at the Mütter Museum in Philadelphia and two of the 140 sections are on loan at the British Museum.[12]
Scientists are currently interested in the possibility that physical differences in brain structure could determine different abilities.[11] One part of the operculum called Broca's area plays an important role in speech production. To compensate, the inferior parietal lobe was 15 percent wider than normal.[13] The inferior parietal region is responsible for mathematical thought, visuospatial cognition, and imagery of movement.