From Eric H. Chudler (University of Washington):
There are 3 published scientific studies that have examined
1) On the brain of a scientist: Albert Einstein (1985)
The scientists counted the number of neurons (nerve cells) and glial cells in four areas of Einstein's brain: area 9 of the cerebral cortex on the right and left hemisphere and area 39 of the cerebral cortex on the right and left hemisphere.
The ratios of neurons to glial cells in Einstein's brain were compared to those from the brains of 11 men who died at the average age of 64.
... there were more glial cells for every neuron in Einstein's brain.
The "normal" brains that were compared to Einstein's may not have
been the best group for comparison.
The average age of these brains
was 12 years younger than Einstein's brain. In fact, the youngest
brain in this group was only 47 years old. It is possible that the
neuron to glial ratio seen in Einstein's brain was quite normal for
his age and that the younger comparison group just did not show these
Also, the paper did not describe the background of the
comparison group. What was their intelligence and cause of death?
Would these factors have anything to do with the observed brain
The "experimental group" had only one subject...Einstein!
Additional studies are needed to see if these anatomical differences are found in other people with conceptual and mathematical skills like Einstein.
It appears that only a very small portion of the four areas of each brain was studied.
The paper states that "Four to six sections were cut from each block, Einstein's and the controls." However, after staining, only ONE section from each block was studied! There is no indication that this single thin section was obtained from similar regions of area 39 and area 9 from the different brains. It is even unclear how much of each section was counted. Moreover, only the ratio of neurons to glial cells was published. The total number of cells that were counted is not given in the paper. This is important to get an idea of how the experimenters came to their conclusions.
It is important to remember that the areas 9 and 39 make important connections with many other areas of the brain. To assign a particular behavior or personality to a single brain area is too simple. Parts of the brain do not act by themselves. Rather, complex behavior is the result of many areas acting together.
2) Alterations in cortical thickness and neuronal density in the frontal cortex of Albert Einstein. (1996)
Einstein's brain weighed only 1,230 grams, which is less than the average adult male brain (about 1,400 grams).
The authors also reported that the thickness of Einstein's cerebral cortex (area 9) was thinner than that of five control brains. However, the DENSITY of neurons in Einstein's brain was greater.
In other words, Einstein was able to pack more neurons in a given area of cortex.
3) The exceptional brain of Albert Einstein (1999)
In this paper, the external surface characteristics of Einstein's brain were compared to those from the brains of 35 men (average age, 57 years old).
Unlike the brain of these 35 men, Einstein's brain had an unusual pattern of grooves (called sulci) on both right and left parietal lobes. This particular area of the parietal lobe is thought to be important for mathematical abilities and spatial reasoning.
Einstein's brain had a much shorter lateral sulcus (*Sylvian fissure) that was partially missing*.
His brain was also 15% wider than the other brains.
The researchers think that these unique brain characteristics may have allowed better connections between neurons important for math and spatial reasoning.
Although these results are interesting, it must be remembered that this study had only ONE brain in the experimental group...Albert Einstein's brain.
It remains to be seen if other mathematical geniuses also show these distinguishing brain characteristics. Moreover, the study did not investigate the brain at a microscopic level. In other words, the study says nothing about how neurons in these brains were connected and of course, could not tell if there were differences in the way the neurons functioned.