for National Geographic News
It may be the most complex structure in the universe, a tangled web of more than a hundred billion nerve cells. For centuries, scientists have studied it, yet very little is known about the way the human brain really works.
Now powerful new computing technology is enabling scientists to learn more about the brain than ever before.
At the forefront is a new initiative to create a software replica of the brain's neocortical column, the smallest network of neurons (nerve cells) and an elementary building block of the mammalian brain.
The project is seen as a first step toward the long-term goal of creating a 3-D computer simulation of the human brain.
"We are not trying to build a copy of the human brain, or some magical artificial intelligence device," said Henry Markram, who heads the Brain Mind Institute at the Ecole Polytechnique Fédérale de Lausanne in Switzerland. His laboratory is collaborating with the computer giant IBM on the project.
"This is really a discovering of how the brain works," Markram said.
More than a hundred billion neurons make up the human brain, and the nerve cells are bunched in neocortical columns. These columns mark a jump in the brain's evolution that occurred 200 million years ago as mammals emerged from reptiles.
Since then the columns have multiplied within the mammalian brain to make more powerful minds.
In primates, and especially humans, this replication continued at such a rapid pace that the neocortex, the largest and most complex part of the brain, folded in on itself to make space for new columns. This is what gives the human brain its wrinkled shape.
The discovery of the neocortical columnwhich is half a millimeter (about two-hundredths of an inch) in diameter and two millimeters (about eight-hundredths inch) long and contains about 60,000 neuronsearned Torsten Wiesel of Rockefeller University in New York the Nobel Prize in 1981.
While scientists are able to make computer simulations of individual neurons, they have not been able to mimic the neocortical column, simply because of its complexity.
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