The sudden emergence of a brain cell "chorus" from the cacophony of normal brain cell activity may enable the brain to pay close attention to one item in a flood of incoming sensory information, according to a report in this week's "Nature."

The report, based on data acquired from monkeys, suggests that a baseball player tracking a fly ball through a cloud-cluttered sky, a driver reaching into a pocket to feel for keys, and a high-school student seeking a cafeteria dish that smells edible could all have something in common: Some of the nerve cells in the cortex, the sophisticated outer layer of the brain, may be sending messages in unison to allow them to pay attention to a single stream of sensory input.

"Every second, we get millions or hundreds of millions of bits of information coming in from our senses," says Ernst Niebur, assistant professor of neuroscience at the Krieger Mind-Brain Institute at The Johns Hopkins University. "And we have to decide, every second, which part of it is important and which part is not important."

"The nerve cells which represent the important information need a way to stand out from the crowd of other information," says Peter Steinmetz, lead author on the paper and a former postdoctoral scholar at the institute. "Firing synchronously like singers in a chorus -- is one way to stand out from the crowd."

Scientists produced the new finding by re-analyzing data gathered over several years. Institute scientists Ken Johnson and Steve Hsiao had been monitoring brain cell activity in monkeys who were performing simple tasks that required them to focus their attention on visual or tactile stimuli. Tasks included identifying which of three white squares of light o
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Contact: Michael Purdy
mcp@jhu.edu
410-516-7160
Johns Hopkins University
7-Mar-2000