Probing the Brain’s Mysteries
New techniques, including advances in brain scans and interconnected databases, are helping to reveal the hidden anatomy of brain wiring. With these efforts, scientists are trying to revolutionize their understanding of how thoughts, memories, and emotions are formed:
For years, researchers have probed the brain with imaging techniques that can pick up simple changes in neural activity, but the fundamental anatomy of thought has eluded detection. No one knows yet exactly how the brain stores information or shapes human nature.
Researchers do believe, however, that all cognition emerges from the interplay of electrochemical impulses along the brain’s circuitry, which can call a word to mind, apply the rules of grammar and voice it aloud in 600 milliseconds.
Among the most complex structures in the universe, the average brain contains about 100 billion specialized cells called neurons — as many cells as stars in the Milky Way linked by 150 trillion or so connections known as synapses. By current means, it could take researchers years to trace the 10,000 or so synapses that branch from just a single neuron. By comparison, the scientists who sequenced the first human genome had to map only three billion base-pair sequences of DNA.
“That is a million times more connections than the genome has letters of DNA,” said computational neuroscientist Sebastian Seung at the Massachusetts Institute of Technology, who is developing ways to automate the mapping of individual synapses.