When looking up the literature on the higher functions of the brain one realizes how unfortunate it is that so much valuable material is not made use of. Men and women who have exhibited special aptitude and powers in various directions that must, according to all we can at present know or infer, have been correlated with special physical developments, probably macroscopic, of the cerebral cortex, are passing away daily. The knowledge which a study of their brains might impart is, however, through social prejudice, forever lost. One or two generalizations are fairly well established and these are almost a priori ones. One is that, generally speaking, the largest brains are those whose possessors are best endowed with intelligence. We may also assume it to be established that this is especially true of those who have been eminent for their achievements in the highest intellectual occupations which may be supposed to call into play and require the development of the most complex and highest mechanisms of the mind. We recognize, too, that a highly-convoluted human brain goes with a higher grade of intelligence as a rule. We know from pathologic observations the location of the special motor and speech centers, and the probable location, in a general way, of the higher intellectual faculties in the prefrontal region, and approximately the location of the sensory functions in other regions. But the physiology of the cerebral convolutions of man in any complete sense is as yet too little known, and especially do we lack the data needed to furnish any correct idea of the structural brain variations connected with the non-pathologic differences observed in different individuals of the same race.
THE BRAINS OF EMINENT MEN.. JAMA. 2008;300(4):447. doi:10.1001/jama.300.4.447