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‘Introspection’ brain networks fully formed at birth
THIS WEEK
Biogas comes in from the cold BC. In colder climates, however, the microbes naturally present in organic matter such as kitchen waste and manure grow too sluggishly for this to be practical. “Their lifestyle is not suited to the demands of
LAUREL McFADDEN struck a match and held it up to a nozzle on a giant tank. A small blue flame flickered into life, indicating that the mixture of mud, ground-up kitchen scraps and water inside the tank was generating methane. In a warm climate, producing biogas in this way is no big deal. However, McFadden’s demonstration took place in Alaska in near-freezing temperatures. The ability to make biogas under such conditions could be hugely significant in cutting reliance on fossil fuels in colder parts of the world. Biogas is generated by microbes when they break down organic matter in airtight tanks called digesters. The process is cheap and can reduce landfill. What’s more, the use of smallscale digesters connected to domestic appliances can cut exposure to harmful smoke given off by other fuels. People have been producing biogas for fuel for centuries. The Assyrians, for example, apparently used it to heat their baths in the 10th century
Newborn brains are wired for consciousness COULD a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other possible aspects of consciousness are fully formed in newborn babies. Certain patterns of low-frequency brain activity, called resting state networks (RSNs), are constantly 14 | NewScientist | 6 November 2010
Xinhua/ZUMApress.com
Sujata Gupta
active, even when a person is asleep. When someone is engaged in a task, there is a drop in the activity of an RSN called the default mode network. This suggests it may be involved in introspective activities like envisioning the future – what some would call a facet of consciousness. Earlier studies suggest that this network only fully develops during childhood, but David Edwards and colleagues at Imperial College London have now shown that it is fully formed at birth. They scanned the brains of 70 premature babies and
our lifestyle,” says Ricardo Cavicchioli, a microbiologist at the University of New South Wales in Sydney, Australia. To get around this problem, researchers have tried housing the digesters in warm locations such as greenhouses. Katey Walter Anthony, an ecologist who worked with McFadden at the University of Alaska Fairbanks, had a radically different idea. She had studied microbes called psychrophiles that live in
permafrost, where they metabolise organic material and release methane as a by-product. Her realisation that these microbes might thrive inside cold digesters led to McFadden’s experiments with digesters containing psychrophile-rich mud from a frozen lake in Alaska. Using a 1000-litre digester, the pair were able to produce 200 to 300 litres of methane per day. Similar-sized digesters in warmer regions can produce 1000 litres of biogas a day – enough to power a fridge for 16 to 20 hours. Anthony and McFadden are now working to increase the yield of their method. If they succeed, their technology could be of huge benefit to people in cooler climes who still rely on fossil fuels and firewood. It is easy enough to find a source of the microbes in frozen soils, and once a culture is thriving in one digester, it can be used to kickstart others. Psychrophiles could also be used in the growing number of industrial biogas plants. At present these have to channel 20 to 40 per cent of the energy they produce into keeping the digesters warm enough for the microbes to grow. If psychrophile-fed digesters become more efficient, these plants could one day feed all the energy they generate into –Cheap, convenient, smoke-free the grid. n
found that while the rates of development varied, RSNs for vision, touch, movement and decisionmaking were largely complete by 40 weeks – the age at which the babies would normally have been born – as was the default mode network. The presence of the default mode network in newborn babies suggests that either “being a fetus is a lot more fun than we remember”, as we could
“Either being a fetus is more fun than we remember or our grasp of what these networks do is mistaken”
lie there thinking about the future, or our current understanding of what these networks do is mistaken, says Edwards. Neurologist Marcus Raichle of Washington University in St Louis, Missouri, who was not involved in the research, advises caution in drawing conclusions from these results. While structures like the default mode network may make consciousness possible, he says, they do not define it. However, the research may ultimately help diagnose and treat neurological conditions like cerebral palsy, Raichle says. Nathan Collins n
Biogas comes in from the cold BC. In colder climates, however, the microbes naturally present in organic matter such as kitchen waste and manure grow too sluggishly for this to be practical. “Their lifestyle is not suited to the demands of
LAUREL McFADDEN struck a match and held it up to a nozzle on a giant tank. A small blue flame flickered into life, indicating that the mixture of mud, ground-up kitchen scraps and water inside the tank was generating methane. In a warm climate, producing biogas in this way is no big deal. However, McFadden’s demonstration took place in Alaska in near-freezing temperatures. The ability to make biogas under such conditions could be hugely significant in cutting reliance on fossil fuels in colder parts of the world. Biogas is generated by microbes when they break down organic matter in airtight tanks called digesters. The process is cheap and can reduce landfill. What’s more, the use of smallscale digesters connected to domestic appliances can cut exposure to harmful smoke given off by other fuels. People have been producing biogas for fuel for centuries. The Assyrians, for example, apparently used it to heat their baths in the 10th century
Newborn brains are wired for consciousness COULD a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other possible aspects of consciousness are fully formed in newborn babies. Certain patterns of low-frequency brain activity, called resting state networks (RSNs), are constantly 14 | NewScientist | 6 November 2010
Xinhua/ZUMApress.com
Sujata Gupta
active, even when a person is asleep. When someone is engaged in a task, there is a drop in the activity of an RSN called the default mode network. This suggests it may be involved in introspective activities like envisioning the future – what some would call a facet of consciousness. Earlier studies suggest that this network only fully develops during childhood, but David Edwards and colleagues at Imperial College London have now shown that it is fully formed at birth. They scanned the brains of 70 premature babies and
our lifestyle,” says Ricardo Cavicchioli, a microbiologist at the University of New South Wales in Sydney, Australia. To get around this problem, researchers have tried housing the digesters in warm locations such as greenhouses. Katey Walter Anthony, an ecologist who worked with McFadden at the University of Alaska Fairbanks, had a radically different idea. She had studied microbes called psychrophiles that live in
permafrost, where they metabolise organic material and release methane as a by-product. Her realisation that these microbes might thrive inside cold digesters led to McFadden’s experiments with digesters containing psychrophile-rich mud from a frozen lake in Alaska. Using a 1000-litre digester, the pair were able to produce 200 to 300 litres of methane per day. Similar-sized digesters in warmer regions can produce 1000 litres of biogas a day – enough to power a fridge for 16 to 20 hours. Anthony and McFadden are now working to increase the yield of their method. If they succeed, their technology could be of huge benefit to people in cooler climes who still rely on fossil fuels and firewood. It is easy enough to find a source of the microbes in frozen soils, and once a culture is thriving in one digester, it can be used to kickstart others. Psychrophiles could also be used in the growing number of industrial biogas plants. At present these have to channel 20 to 40 per cent of the energy they produce into keeping the digesters warm enough for the microbes to grow. If psychrophile-fed digesters become more efficient, these plants could one day feed all the energy they generate into –Cheap, convenient, smoke-free the grid. n
found that while the rates of development varied, RSNs for vision, touch, movement and decisionmaking were largely complete by 40 weeks – the age at which the babies would normally have been born – as was the default mode network. The presence of the default mode network in newborn babies suggests that either “being a fetus is a lot more fun than we remember”, as we could
“Either being a fetus is more fun than we remember or our grasp of what these networks do is mistaken”
lie there thinking about the future, or our current understanding of what these networks do is mistaken, says Edwards. Neurologist Marcus Raichle of Washington University in St Louis, Missouri, who was not involved in the research, advises caution in drawing conclusions from these results. While structures like the default mode network may make consciousness possible, he says, they do not define it. However, the research may ultimately help diagnose and treat neurological conditions like cerebral palsy, Raichle says. Nathan Collins n