A Hands-On Approach to Studying the Brain, Even Einstein’s – New York Times
“…Dr. Witelson is known not only for her brain bank. She has also been in the forefront of controversial studies on the biological basis of intelligence, sex differences in the brain and sexual orientation.
While her N.I.H. study has yet to yield many answers on why language is lateralized, she said something unexpected “fell out” of the research: marked differences between male and female brains.
In 1995, after a 10-year study, Dr. Witelson published findings showing that on average the packing density of neurons was 12 percent greater in the adult female brain than in the adult male brain in the language region of the temporal lobe. A subsequent study of the frontal lobes, soon to be published, revealed similar sex differences.
On first interpretation, she said, this might lead to the conclusion that a woman’s brain is more tightly packed with neurons simply to make up for the well-documented fact that the average female brain is 10 percent smaller than the male brain.
“But that’s not correct,” she said, “because only some of the cortical layers show the difference.”
Layers 2 and 4, those important in processing the input of information, exhibited the differences in neuron capacity.
“Knowing that,” Dr. Witelson said, “one can ask the question of whether the processing of speech sounds could be related to the anatomy, and in fact that’s what we’re doing now.”
Sex differences also turned up in a number of other studies.
In 2005 Dr. Witelson and her colleagues reported that verbal ability was correlated with brain volume, but more strongly in women than in men. And they announced findings indicating that extremely premature birth affects the brain development of boys more adversely than girls.
Though she says the differences among female and male brains should not be discussed in terms of “better” and “worse,” they cannot be denied.
For that reason, her work was often cited by defenders of the former Harvard president Lawrence H. Summers after his suggestion that innate differences might help explain the gender gap on science faculties.
Interviewed on “The NewsHour With Jim Lehrer” on PBS in February 2005, Dr. Witelson said, “If we’re going to try to understand the disparity between the number of women and men in different professions, and this would go for positions way beyond just academia, we have to put all the factors on the table.”
In a recent interview, she said, “It’s clear societal influences are relevant, but that doesn’t preclude the possibility that there are also contributing factors from nature.”
Dr. Witelson does not have a female genius in her brain bank. She is considering broadening the demographic, seeking exceptional individuals regardless of age or sex in a wide spectrum of fields: language, music, chess, even professional sports.
She has not met many of the people whose brains she studies. (Dr. Coxeter was an exception.) But the fact that she is handling the essence of their individualism sometimes gives her pause.
“I have to admit,” she said, “when I saw Einstein’s brain, that was a pretty strong feeling. I realized this was the brain that had provided our current conception of the universe.”
This is the last third of the article. The whole thing is HERE.