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| SCIENCE & TECHNOLOGY |
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Humans cannot multitask
THIS UNIVERSE |
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Humans cannot multitask
THE human mind may be inherently incapable of dealing with more than two tasks at a time according to a study showing that “multi-tasking” skills are limited by the physical division of the brain into two hemispheres. Scientists have found that when people have to carry out two tasks simultaneously their brains divide each job up so that one is performed largely by the left side of the brain and the other is carried out mainly on the right. The study suggests that this basic division of the brain into two halves may explain why human beings tend to prefer a simple choice between two options rather than three or more. It might even explain why the Liberal Democrats, as the third political party, find it hard to get a look in at general elections. Sylvain Charron and Etienne Koechlin of France’s National Institute of Health and Medical Research in Paris, discovered the way the brain divides up two simultaneous tasks. They asked 32 volunteers to carry out two different mental puzzles while their brains were being scanned by an MRI machine. “Each subject was performing two tasks concurrently. One task was to pair upper case letters and the other task was to pair lower case letters together. It was a very simple task and the subjects had to switch back and forth between them,” Dr Koechlin said. “We motivated them with a reward if they made no errors between trials. It was a monetary reward actually, so when the subject made an error on one of the tasks, their reward was less. We rewarded brain activity and at the same time we monitored the subjects’ errors, reaction time and so on. So we could measure performance and we found that a larger reward was associated with a better
performance,” he said. The study, published in the journal Science, focused on the medial frontal cortex, which lies at the front of the brain above the eyes. It is this part of the brain that is thought to drive the pursuit of rewards associated with carrying out a task. The medial frontal cortex is divided into two halves, one for each side of the brain, and the scientists found when they monitored a subject’s brain activity in the MRI scanner that the right side of the frontal cortex tended to be active when the subject was carrying out one task, and the left side was more active when carrying out the other. All volunteers were right-handed so there was no confusion about which part of the brain was controlling each task — the right hand is controlled by the left side of the brain and vice versa. “We found that brain activity increased with rewards and expectations in the medial frontal cortex. We found in the left hemisphere that the activity increased as the reward value of one task increased, but not the other task, whereas in the right hemisphere the brain activation was related to the reward value of the other task,” Professor Koechlin said. “The two hemispheres co-operated when there was only one task. But in two tasks, one hemisphere covers the reward of one task and the other hemisphere covers the reward of the other.” “The human prefrontal function seems to be built to control two tasks simultaneously. It means in everyday behaviour we can readily switch between two tasks but not between three. With three tasks the division is limited to only two hemispheres, so there is a problem,” he said. This physical restraint on doing three things at once may have wider implications for human reasoning. “We know that subjects have difficulty deciding between more than two options and our study provides a possible explanation for why we like such binary decisions —because the brain’s frontal lobe function is fundamentally binary in nature,” Professor Koechlin said. And, contrary to popular belief, they found no differences in multi-tasking skills between the sexes, meaning no excuses for men from now
on. — By arrangement with
The Independent
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Global floating ice in “constant retreat” LONDON:
The world’s floating ice is in “constant retreat,” showing an instability which will increase global sea levels, according to a report published in Geophysical Research Letters on Wednesday. Floating ice had disappeared at a steady rate over the past 10 years, according to the first measurement of its kind. World’s largest telescope to be built in Chile SANTIAGO: The world’s largest
telescope will be built in Chile’s northern desert at a cost over $1 billion, the European Southern Observatory said on Monday, and will set its sights on discovering other worlds like our own. The 42-meter European Extremely Large Telescope will watch the skies for exo-planets, or planets around stars, as well as seek to unravel the mystery of dark matter and dark energy. NASA’s final shuttle flight slips to November CAPE CANAVERAL, Florida: NASA’s last space shuttle mission will be delayed until November so scientists can adapt a $2 billion particle detector for an extended life aboard the International Space Station, officials said Monday. Three more shuttle flights remain and the space agency had planned to close out the program by September 30 with a final mission by shuttle Discovery to resupply the orbital outpost. Florida faces new cotton pest NEW YORK: The cotton seed bug, a pest that has not been found in the United States, has been found for the first time in Florida, agriculture officials said. The Florida Department of Agriculture and Consumer Services said in a statement on Friday the pest was found by an inspector of the U.S. Agriculture Department among cotton plants in the Florida Keys. Ukraine needs more Chernobyl funds KIEV: Ukraine needs more international cash to keep safe the concrete case over the Chernobyl nuclear plant’s fourth reactor which exploded 24 years ago, President Viktor Yanukovich said Monday. Thousands of metric tons of toxic nuclear dust billowed across Ukraine, Russia and Belarus in the world’s worst civil nuclear disaster on April 26, 1986.
— Reuters |
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THIS UNIVERSE If a light is switched on
or off we are able to detect even if our eyes are closed. How? I think the reason should be obvious. Our eyelids are not completely opaque; some light always filters through even though its colour is slightly reddish. That is enough to tell us whether the room light is on or off. We always say that there is no life possible on planets like Mercury, Venus, etc as they are very near to Sun or they lack oxygen. Can’t there be such creatures that do not require oxygen for their survival? You are right to be sceptical. A century ago we would have thought that no living things could be born at the bottom of the ocean where there is no light and at places near the subterranean volcanoes with water and steam at several hundred degrees Celsius. But we have been surprised because these very volcanoes provide the energy and nutrients to abundant forms of life there. Similarly, there is life in the frozen wastes of Antarctica and some people have claimed evidence of life at altitudes of 1,50,000 feet. But all these living things in extreme climates of the earth still represent examples of the same kind of life we are familiar with, even if their manifestations are different. Therefore I have a problem imagining our kind of life on uniformly inhospitable conditions of Mercury or Venus. People have surmised that there might be self-replicating systems of silicon and oxygen. I do not know of any examples of those. Origin of life might still be a mystery. But availability of the basic materials like hydrogen, oxygen and carbon is not a problem, because these are some of the most abundant elements in the universe. There are also conditions and happenings in the interstellar space that lead to abundant production and retention of organic molecules. But life is more complicated and it may not be surprising that we have not yet found any location other than our planet where life grew and ultimately formed an intelligent civilization. On the other hand, I begin to wonder whether such civilizations have a relatively short lifespan; by short I mean less than a few million years! Look at the only example of a technological and intelligent civilisation we represent. We became technological less than a hundred years ago and it seems a bit problematic that would survive another thousand years! Nuclear and other weapons of mass destruction, including global warming, would make a lifetime longer than a million years rather unlikely - unlikely at least as a technological intelligent civilization. |
