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Hello All; More interesting news from that conference in Baltimore. Janet ---------------------------------------------------------------------- Found at last: the brain's own egg timer ---------------------------------------------------------------------- Copyright ) 1996 Nando.net Copyright ) 1996 The Associated Press BALTIMORE (Feb 12, 1996 1:53 p.m. EST) -- Scientists have located the brain's stopwatch -- the spot that calculates whether you've got enough time to bolt across the street in front of a car or run to the bathroom during a commercial. It's called the interval timer and its job is to keep track of the minutes and seconds that make up everyday life. Unlike the body's other timekeeper -- the circadian clock, which keeps hormones, digestion, sleep and other functions running on a 24-hour cycle -- the interval clock measures much shorter times. It allows humans and other animals to learn and survive in their native habitat, whether that's the rain forest or the freeway. In the wild, for instance, animals must keep track of how much time passes between catching prey. This is how they know whether to keep hunting in the same place or move on. Humans put this faculty to other uses. "Many gourmet cooks learn the specific duration for all the critical ingredients going into the dish," said Dr. Warren Meck of Duke University. "They don't set up 20 egg timers on their kitchen counter. They learn to juggle in their heads different durations simultaneously." Even non-gourmet cooks can boil an egg, brew coffee and make toast, all at the same time. That's because they have an interval timer. Meck described the location of the timer -- in the dead center of the brain -- Sunday at the annual meeting of the American Association for the Advancement of Science. He and colleagues used magnetic resonance imaging to study the activity of the brain. They asked volunteers to squeeze a ball every 11 seconds. Then they watched what happened inside their heads. The scans revealed that the striatum, a structure deep inside the brain, was working hard during this exercise. In this, as with many other things, human brains work a lot like rats'. Meck's earlier research showed that rats trained to press a lever for food after a specified time used the same part of their brains. More confirmation of the relevance of this for humans comes from separate studies by Dr. John Gibbon of Columbia University. He looked at the ability of people with Parkinson's disease to keep track of time. Gibbons found that when Parkinson's patients are off dopamine replacement therapy, they have trouble measuring short intervals. Their disease results from damage to the same part of the brain where Meck believes he has located the interval clock. The discovery of the interval clock has no practical uses for now. However, it may help scientist someday craft better treatments for Parkinson's patients and others who suffer damage in this part of the brain. ---------------------------------------------------------------------- Janet Paterson - 48 - 7 - [log in to unmask] - Bermuda