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Poverty can sap people's ability to think clearly
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neurdein/roger-viollet/topfoto
VICTORIAN skiing holidays to Europe may be partially to blame for the rapid retreat of glaciers in the Alps during the mid-19th century. From 1865, Alpine glaciers started to shrink to lengths not seen in the previous 500 years, a trend that continues today. This has puzzled climatologists as records show local temperatures were cool in the decades before the glaciers retreated, meaning something else must have melted them. Mark Flanner of the University of Michigan at Ann Arbor and his colleagues say soot particles from increased rail transport, the booming tourist industry and coal fires – all brought about by the budding industrial revolution – are to blame, especially from coal burned on the doorstep of the Alps. Black soot landing on a glacier reduces its reflectivity, causing it to absorb more energy from the sun and melt. The team studied ice cores from the glaciers and found that soot concentrations in the ice increased rapidly around the time the glaciers began retreating. Computer simulations showed these levels were high enough to melt almost a metre extra of glacier each year (PNAS, DOI: 10.1073/ pnas.1302570110). “This is a sharp jolt to the system, a very rapid and large increase in soot over a very short period of time,” says Flanner.
Being poor can sap your ability to think clearly IT’S the cruel cycle of poverty. The many challenges that come with being poor can sap people’s ability to think clearly. Sociologists have long known that poor people are less likely to take medications, keep appointments, or be attentive parents. “Poor people make poorer decisions. They do. The question is why,” says Timothy Smeeding, director of the Institute for Research on Poverty at the University of WisconsinMadison. But does bad decisionmaking help cause poverty, or
does poverty interfere with decision-making? To find out, Eldar Shafir at Princeton University and his colleagues took advantage of a natural experiment. Small-scale sugar-cane farmers in Tamil Nadu in southern India receive most of their year’s income all at once, shortly after the annual harvest. As a result, the same farmer can be poor before harvest but relatively rich afterwards. The researchers visited 464 farmers in 54 villages both before and after harvest. At each
visit, they gave the farmers two tests of their cognitive ability, such as a pattern-matching test. The farmers scored significantly lower – equivalent to a 13-point drop in IQ – on the tests before the harvest, when money was tight, suggesting that their worries made it harder to think clearly (Science, doi.org/nng). The most likely explanation is that people have a limited amount of “mental bandwidth”, and financial worries leave less available for other cognitive tasks, says Shafir. NASA/CXC/MIT/F. K. Baganoff et al.
Victorian skiers made Alps melt
Train your brain – one skill at a time BRAIN training might keep you mentally young, but only if you exercise one skill at a time. Video games that claim to boost your smarts are popular but a study in 2010 of 11,000 people found that typical brain-training games improved cognitive ability only by the same amount as surfing the internet. However, the volunteers in that study trained using games that targeted several skills at once, so Joaquin Anguera at the University of California in San Francisco and his colleagues wondered whether focusing on just one might give better results. A group of 60 people aged between 60 and 85 played a game solely designed to improve multitasking skills, three times a week for a month. A month later, they were significantly better not only at the game itself, which you would expect, but also in tests that gauged their ability to concentrate and juggle several tasks at once. Players were still showing improvements in these skills six months later. The results suggest that singlefocus games might indeed be useful therapies to stave off cognitive decline (Nature, DOI: 10.1038/nature12486).
Milky Way’s black hole is a picky eater OUR galaxy’s central black hole is finicky, refusing to eat most of its meals because the food is too hot. Large galaxies like the Milky Way are thought to have supermassive black holes at their cores. Some of these are enthusiastic eaters that shine brightly in X-rays as they feast. The Milky Way’s relatively dim black hole is not a gorger, but it does have a steady food source. A crowded disc of massive stars spins around it, and they should spew out enough gas in stellar winds to provide about four Earths’ worth of meals over a year. But if it were swallowing that
much stuff, it would shine 100 million times brighter than it does. To find out what’s going on, Daniel Wang at the University of Massachusetts Amherst and his colleagues used NASA’s Chandra X-ray Observatory to measure the temperature and abundance of gas near the black hole. They found that less than 1 per cent of the stuff ultimately gets close enough to be eaten (Science, doi.org/nnj). The team thinks that, at 10 million °C, the gas is too hot and tenuous to fall in readily, so our black hole, which would eat colder meals more easily, can’t swallow much of it.
7 September 2013 | NewScientist | 17
neurdein/roger-viollet/topfoto
VICTORIAN skiing holidays to Europe may be partially to blame for the rapid retreat of glaciers in the Alps during the mid-19th century. From 1865, Alpine glaciers started to shrink to lengths not seen in the previous 500 years, a trend that continues today. This has puzzled climatologists as records show local temperatures were cool in the decades before the glaciers retreated, meaning something else must have melted them. Mark Flanner of the University of Michigan at Ann Arbor and his colleagues say soot particles from increased rail transport, the booming tourist industry and coal fires – all brought about by the budding industrial revolution – are to blame, especially from coal burned on the doorstep of the Alps. Black soot landing on a glacier reduces its reflectivity, causing it to absorb more energy from the sun and melt. The team studied ice cores from the glaciers and found that soot concentrations in the ice increased rapidly around the time the glaciers began retreating. Computer simulations showed these levels were high enough to melt almost a metre extra of glacier each year (PNAS, DOI: 10.1073/ pnas.1302570110). “This is a sharp jolt to the system, a very rapid and large increase in soot over a very short period of time,” says Flanner.
Being poor can sap your ability to think clearly IT’S the cruel cycle of poverty. The many challenges that come with being poor can sap people’s ability to think clearly. Sociologists have long known that poor people are less likely to take medications, keep appointments, or be attentive parents. “Poor people make poorer decisions. They do. The question is why,” says Timothy Smeeding, director of the Institute for Research on Poverty at the University of WisconsinMadison. But does bad decisionmaking help cause poverty, or
does poverty interfere with decision-making? To find out, Eldar Shafir at Princeton University and his colleagues took advantage of a natural experiment. Small-scale sugar-cane farmers in Tamil Nadu in southern India receive most of their year’s income all at once, shortly after the annual harvest. As a result, the same farmer can be poor before harvest but relatively rich afterwards. The researchers visited 464 farmers in 54 villages both before and after harvest. At each
visit, they gave the farmers two tests of their cognitive ability, such as a pattern-matching test. The farmers scored significantly lower – equivalent to a 13-point drop in IQ – on the tests before the harvest, when money was tight, suggesting that their worries made it harder to think clearly (Science, doi.org/nng). The most likely explanation is that people have a limited amount of “mental bandwidth”, and financial worries leave less available for other cognitive tasks, says Shafir. NASA/CXC/MIT/F. K. Baganoff et al.
Victorian skiers made Alps melt
Train your brain – one skill at a time BRAIN training might keep you mentally young, but only if you exercise one skill at a time. Video games that claim to boost your smarts are popular but a study in 2010 of 11,000 people found that typical brain-training games improved cognitive ability only by the same amount as surfing the internet. However, the volunteers in that study trained using games that targeted several skills at once, so Joaquin Anguera at the University of California in San Francisco and his colleagues wondered whether focusing on just one might give better results. A group of 60 people aged between 60 and 85 played a game solely designed to improve multitasking skills, three times a week for a month. A month later, they were significantly better not only at the game itself, which you would expect, but also in tests that gauged their ability to concentrate and juggle several tasks at once. Players were still showing improvements in these skills six months later. The results suggest that singlefocus games might indeed be useful therapies to stave off cognitive decline (Nature, DOI: 10.1038/nature12486).
Milky Way’s black hole is a picky eater OUR galaxy’s central black hole is finicky, refusing to eat most of its meals because the food is too hot. Large galaxies like the Milky Way are thought to have supermassive black holes at their cores. Some of these are enthusiastic eaters that shine brightly in X-rays as they feast. The Milky Way’s relatively dim black hole is not a gorger, but it does have a steady food source. A crowded disc of massive stars spins around it, and they should spew out enough gas in stellar winds to provide about four Earths’ worth of meals over a year. But if it were swallowing that
much stuff, it would shine 100 million times brighter than it does. To find out what’s going on, Daniel Wang at the University of Massachusetts Amherst and his colleagues used NASA’s Chandra X-ray Observatory to measure the temperature and abundance of gas near the black hole. They found that less than 1 per cent of the stuff ultimately gets close enough to be eaten (Science, doi.org/nnj). The team thinks that, at 10 million °C, the gas is too hot and tenuous to fall in readily, so our black hole, which would eat colder meals more easily, can’t swallow much of it.
7 September 2013 | NewScientist | 17