When geneticists study individual genes to see what they do, the most effective method is to simply delete them and see what happens. Doing these so-called “knock-out” experiments thousands of times over can give scientists a fairly complete picture of how a genome works.
Wouldn’t it be great if all scientific results could be so straight-forward? Cut a couple of atoms out of a molecule to see how the chemistry is affected. Remove a whole civilization to see how the world reacts. Take out pieces of the brain to see what each area does.
Actually, that last one isn’t so far-fetched.
In a recent study from the University of Illinois, in fact, neuroscience professor Aron Barbey did just that. Well, at least he did in principle. He didn’t go into people’s brains and conduct localized lobotomies. It would be a teeny bit tough to get a patient’s consent for that one.
Luckily, the Vietnam War did it for him.
Barbey gathered 182 Vietnam veterans with highly localized brain damage from penetrating head injuries and put them to the test. Using MRI scans, he divided the brain into 3,000 different three-dimensional units called voxels. Then, he compared cognitive abilities and voxels were damaged in each Veteran to come up with a general map of where our higher brain functions lay.
The structures for general intelligence aren’t as wide-spread throughout a network as you might expect. Instead, a few structures were identified, located primarily within the left prefrontal cortex (behind the forehead), left temporal cortex (behind the ear) and left parietal cortex (at the top rear of the head) and in “white matter association tracts” that connect them.
What’s more, these regions overlapped with brain regions for planning, self-control and other aspects of executive function.
The study provides new evidence that intelligence relies not on one brain region or even the brain as a whole, Barbey said, but involves specific brain areas working together in a coordinated fashion.
I guess it just goes to show you how much smarter righties are than lefties. I suppose it also shows why those with a “dominant left brain” are more apt for logic, math and the like.
Maybe there really is something to that whole left brain/right brain saying.