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Positive feedback gives kids with ADHD a headstart
heidi bradner/panos
IN BRIEF Positive feedback boosts attention
Reindeer gained UV-vision after moving to the Arctic REINDEER see their world in glorious ultraviolet, helping them to find food and avoid predators. Most mammals, including humans, see using light from the visible part of the spectrum; ultraviolet light, which has a shorter wavelength, is invisible. But not so for reindeer, says Glen Jeffery of University College London. The frozen wastes of the Arctic reflect around 90 per cent of the UV light that hits them; snow-free land typically reflects only a few per cent. So Jeffery and colleagues wondered whether reindeers had adapted to their UV-rich world. In dark conditions, they shone LED
lights of different wavelengths, including UV, into the eyes of 18 anaesthetised reindeers while recording with an electrode whether nerves in the eye fired, indicating that the light had been seen. The UV light triggered a response in the eyes of all the reindeer (Journal of Experimental Biology, DOI: 10.1242/jeb.053553). “Since migrating to the Arctic 10,000 years ago, these animals have adapted incredibly quickly,” says Jeffery. The team’s experiments with a UV camera in the Arctic suggest why. They showed that urine – a sign of predators or potential mates – and lichens – a major food source for reindeers in the winter months – absorb UV light, making them appear black in contrast to the UV-reflecting snow. “This is the first time we have got a real handle on why a mammal uses UV light,” Jeffery says.
Binary stars behind puffy planet puzzle MANY Jupiter-like exoplanets are much larger than they ought to be. Now one astronomer thinks he knows why. Since planets usually form at the same time as stars, astronomers can tell how old and therefore how hot and puffy the gas giants should be. But many of the recently discovered gaseous exoplanets are larger than expected. 20 | NewScientist | 4 June 2011
Eduardo Martin of the Institute of Astrophysics of the Canary Islands believes this is because the puffy planets formed from the gas and dust ejected when two binary stars merged. This would make the planets much younger than their hosts, which would explain their unusual heat and puffiness. He presented his findings at the American Astronomical Society meeting in Boston last week.
“The process is possible, but it’s unlikely to explain the multitude of inflated planets that we’re now discovering,” says Adam Burrows of Princeton University, who was not involved in the research. Martin agrees that there are too few binary systems to account for the number of puffy planets seen. But he thinks that’s because the number of binaries has been underestimated, so he is now searching for the “missing” population.
POSITIVE feedback could help children at risk of attention problems excel at learning exercises, maybe even enabling them to overtake their peers. Previous research has shown that children with a longer variant of the dopamine D4 receptor gene (DRD4) are more likely to do poorly in school due to shorter attention spans. So Adriana Bus at Leiden University in the Netherlands compared how well 182 4-yearolds, 40 per cent with the variant, performed in electronic reading games when supportive feedback was switched on or off. While positive feedback helped all the children to learn, those with the DRD4 variant did significantly better than their peers (Mind, Brain and Education, DOI: 10.1111/j.1751228X.2011.01112.x). The DRD4 variant is known to alter dopamine signalling in the brain, which may make these children more sensitive to positive feedback, Bus says.
Why intolerance should be tolerated INTOLERANCE may well serve a purpose, according to Michele Gelfand at the University of Maryland in College Park. She surveyed 6800 people in 33 countries and found that the populations of countries that had faced, or are facing, threats such as natural disasters, disease or war tended to be more conformist. Becoming socially strict may be a healthy response to threats and offer a society a better chance of survival, Gelfand says (Science, DOI: 10.1126/science.1197754). But Randy Thornhill of the University of New Mexico, Albuquerque, points out that some threats – like food shortages – would be better handled by the sort of tolerance that would allow new survival strategies to develop.
IN BRIEF Positive feedback boosts attention
Reindeer gained UV-vision after moving to the Arctic REINDEER see their world in glorious ultraviolet, helping them to find food and avoid predators. Most mammals, including humans, see using light from the visible part of the spectrum; ultraviolet light, which has a shorter wavelength, is invisible. But not so for reindeer, says Glen Jeffery of University College London. The frozen wastes of the Arctic reflect around 90 per cent of the UV light that hits them; snow-free land typically reflects only a few per cent. So Jeffery and colleagues wondered whether reindeers had adapted to their UV-rich world. In dark conditions, they shone LED
lights of different wavelengths, including UV, into the eyes of 18 anaesthetised reindeers while recording with an electrode whether nerves in the eye fired, indicating that the light had been seen. The UV light triggered a response in the eyes of all the reindeer (Journal of Experimental Biology, DOI: 10.1242/jeb.053553). “Since migrating to the Arctic 10,000 years ago, these animals have adapted incredibly quickly,” says Jeffery. The team’s experiments with a UV camera in the Arctic suggest why. They showed that urine – a sign of predators or potential mates – and lichens – a major food source for reindeers in the winter months – absorb UV light, making them appear black in contrast to the UV-reflecting snow. “This is the first time we have got a real handle on why a mammal uses UV light,” Jeffery says.
Binary stars behind puffy planet puzzle MANY Jupiter-like exoplanets are much larger than they ought to be. Now one astronomer thinks he knows why. Since planets usually form at the same time as stars, astronomers can tell how old and therefore how hot and puffy the gas giants should be. But many of the recently discovered gaseous exoplanets are larger than expected. 20 | NewScientist | 4 June 2011
Eduardo Martin of the Institute of Astrophysics of the Canary Islands believes this is because the puffy planets formed from the gas and dust ejected when two binary stars merged. This would make the planets much younger than their hosts, which would explain their unusual heat and puffiness. He presented his findings at the American Astronomical Society meeting in Boston last week.
“The process is possible, but it’s unlikely to explain the multitude of inflated planets that we’re now discovering,” says Adam Burrows of Princeton University, who was not involved in the research. Martin agrees that there are too few binary systems to account for the number of puffy planets seen. But he thinks that’s because the number of binaries has been underestimated, so he is now searching for the “missing” population.
POSITIVE feedback could help children at risk of attention problems excel at learning exercises, maybe even enabling them to overtake their peers. Previous research has shown that children with a longer variant of the dopamine D4 receptor gene (DRD4) are more likely to do poorly in school due to shorter attention spans. So Adriana Bus at Leiden University in the Netherlands compared how well 182 4-yearolds, 40 per cent with the variant, performed in electronic reading games when supportive feedback was switched on or off. While positive feedback helped all the children to learn, those with the DRD4 variant did significantly better than their peers (Mind, Brain and Education, DOI: 10.1111/j.1751228X.2011.01112.x). The DRD4 variant is known to alter dopamine signalling in the brain, which may make these children more sensitive to positive feedback, Bus says.
Why intolerance should be tolerated INTOLERANCE may well serve a purpose, according to Michele Gelfand at the University of Maryland in College Park. She surveyed 6800 people in 33 countries and found that the populations of countries that had faced, or are facing, threats such as natural disasters, disease or war tended to be more conformist. Becoming socially strict may be a healthy response to threats and offer a society a better chance of survival, Gelfand says (Science, DOI: 10.1126/science.1197754). But Randy Thornhill of the University of New Mexico, Albuquerque, points out that some threats – like food shortages – would be better handled by the sort of tolerance that would allow new survival strategies to develop.