Men's, Women's and Einstein's Brain

Interesting article about Sandra Witelson's brain research, which looks at brain differences between men and women. She also got a hold of Einstein's brain and looked at that.

Men vs. Women

Men's brains, for instance, are typically bigger — but on the whole, no smarter.

All in all, men appear to have more gray matter, made up of active neurons, and women more of the white matter responsible for communication between different areas of the brain.

Men and women appear to use different parts of the brain to encode memories, sense emotions, recognize faces, solve certain problems and make decisions. Indeed, when men and women of similar intelligence and aptitude perform equally well, their brains appear to go about it differently, as if nature had separate blueprints, researchers at UC Irvine reported this year.

Among women, the neurons in the cortex were closer together. There were as many as 12% more neurons in the female brain.

Perhaps, she speculated, these neuron-rich layers in an area associated with perception and speech were the reason women scored more highly than men on tasks involving language and communication.

As she matched the brain specimens to the intellectual qualities of their owners, she discovered that differences in the size of the corpus callosum were linked to IQ scores for verbal ability, but only in women. She found that memory was linked to how tightly neurons were packed, but only in men.

Witelson determined that brain volume decreased with age among men, but hardly at all among women. Moreover, those anatomical changes appeared to be closely tied to a gradual decline in mental performance in men. "There is something going on in the male brain," she said, "that is not going on in the female brain."

Einstein's Brain

At Princeton Hospital, Harvey weighed Einstein's brain on a grocer's scale. It was 2.7 pounds — less than the average adult male brain.

She found that one portion of Einstein's brain perhaps related to mathematical reasoning — the inferior parietal region — was 15% wider than normal.

Witelson also found that it lacked a fissure that normally runs along the length of the brain. The average human brain has two distinct parietal lobe compartments; Einstein's had one.

And a couple of good old random brain stats:

In the prime of life, the cerebral cortex contains 25 billion neurons linked through 164 trillion synapses.

Thoughts thread through 7.4 million miles of dendrite fibers and 62,000 miles of axons so compacted that the entire neural network is no larger than a coconut.

Via LA Times