Despite the advancements of modern medicine, the wrinkled, twisted expanse of the human noodle has largely been an unknown frontier, with sparse areas and regions hitherto. In the past, scientists have only plotted sections based on a single type of brain feature, such as cell structures, brain topography, or identified functions. But now, in a comprehensive analysis of 210 healthy brains published in Wednesday Nature, researchers have pooled such datasets and drawn an inclusive map of the provinces of the mind.
The newly inked atlas, from the National Institutes of Health’s Human Connectome Project, more than doubles the identified realm of the outer shell of the human brain, the cerebral cortex. This is the dominant part of the human brain, responsible for the higher functions of our mind such as language, consciousness, information processing and problem solving. The map shows 360 cortex regions or 180 symmetrical, paired regions in each hemisphere, of which 83 were known and 97 new.
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The image shows a multimodal human cortical parcellation of 180 regions on the surfaces of the left and right hemispheres. Colors indicate to what extent the areas at rest are associated with auditory (red), sensation (green), visual (blue). (The brain never ceases to amaze us.)
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This image shows a map of the myelin content (red, yellow are high myelin; indigo and blue are low myelin) in the left hemisphere of the cerebral cortex.
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The image shows the pattern of brain activation (red, yellow) and deactivation (blue, green) in the left hemisphere when listening to stories in the MRI scanner.
Matthew F. Glasser, David C. Van Essen
While the new map is still a first draft, to be tweaked and honed with more research, the study authors hope the cerebral sketch can speed up the pace of understanding how the mind’s hardware works. In addition, it could provide a guide to neurosurgeons’ scalpels and more detail for researchers studying how primate brains evolved.
Led by neuroscientists David Van Essen and Matthew Glasser of Washington University in St. Louis, the study required high-resolution images of the brains of healthy adult participants. The researchers collected snapshots of brain cell organization and connections, activity during various mental activities and levels of neuron insulator, the fatty sheaths of myelin that enhance signaling. The researchers then trained a machine-learning algorithm to trace the boundaries of brain regions.
Once done, the program was able to quickly detect 96.6 percent of regions in new brains. However, the areas of the regions varied from person to person, which could provide fodder for studying the underpinnings of differences between mental abilities and disease risk.
Nature2016. DOI: 10.1038/nature18933 (About DOIs).
Frame image by Matthew F. Glasser, David C. Van Essen