A detailed new map lays out the landscape of the cerebral cortex—the outermost layer of the brain and the dominant structure involved in sensory perception and attention, as well as language, tool use, and abstract thinking.
With the features of a typical brain demarcated in painstaking detail, the new map will be a boon to researchers studying brain disorders such as autism, schizophrenia, dementia, and epilepsy. Scientists will be able to use it to understand differences in the brains of patients with these diseases compared with adults who are healthy. It also will accelerate progress in deciphering the workings of the healthy brain and elucidating what makes us unique as a species.
The new map, reported in Nature, divides both the left and right cerebral hemispheres into 180 areas based on physical differences (such as the thickness of the cortex), functional distinctions (such as which areas respond to language stimuli), and differences in the connections of the areas. Brain cartography is not as simple as noting a “mountain” over here and a “river” over there, since much of the brain looks superficially the same.
The map is more akin to a map showing state borders than topographic features; the most important divisions are invisible from the sky but extremely important all the same.
The researchers drew upon data and methods generated by the Human Connectome Project, a five-year study led by David Van Essen, the senior author of this paper and professor of neuroscience at Washington University School of Medicine in St. Louis,. The Human Connectome Project used a powerful, custom-built MRI machine to map the brains of 1,200 young adults. This study complements the Human Connectome Project by carefully delineating the brain regions so that their connections can be more accurately mapped.
“The brain is not like a computer that can support any operating system and run any software,” says Van Essen. “Instead, the software—how the brain works—is intimately correlated with the brain’s structure—its hardware, so to speak. If you want to find out what the brain can do, you have to understand how it is organized and wired.”
