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5 July 2014 | NewScientist | 11 NASA/JPL-CALTECH/UCLA you turn the key and it all switches on and works together. So while consciousness is a complicated process created via many structures and networks – we may have found the key.” Awake but unconscious Counter-intuitively, Koubeissi’s team found that the woman’s loss of consciousness was associated with increased synchrony of electrical activity, or brainwaves, in the frontal and parietal regions of the brain that participate in conscious awareness. Although different areas of the brain are thought to synchronise activity to bind different aspects of an experience together, too much synchronisation seems to be bad. The brain can’t distinguish one aspect from another, stopping a cohesive experience emerging. Since similar brainwaves occur during an epileptic seizure, Koubeissi’s team now plans to investigate whether lower frequency stimulation of the claustrum could jolt them back to normal. It may even be worth trying for people in a minimally conscious state, he says. “Perhaps we could try to stimulate this region in an attempt to push them out of this state.” Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn’t represent a “normal” brain, he says. However, he points out that the interesting thing about this study is that the person was still awake. “Normally when we look at conscious states we are looking at awake versus sleep, or coma versus vegetative state, or anaesthesia.” Most of these involve changes of wakefulness as well as consciousness but not this time, says Seth. “So even though it’s a single case study, it’s potentially quite informative about what’s happening when you selectively modulate consciousness alone.” “Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection to consciousness. “Ultimately, if we know how consciousness is created and which parts of the brain are involved then we can understand who has it and who doesn’t,” says Koch. “Do robots have it? Do fetuses? Does a cat or dog or worm? This study is incredibly intriguing but it is one brick in a large edifice of consciousness that we’re trying to build.” n IT HAS been called a bruise on the sky – a curious cold spot in the afterglow of the big bang that has sparked wild cosmic theories attributing it to a run-in with another universe or a wrinkle in space-time. Now it seems the answer may be a little more mundane: the biggest known hole in the universe. The cold spot appears in maps of the cosmic microwave background (CMB), the earliest light emitted in the universe. Temperature variations in the light show up as a mottled pattern in the maps, which can be explained if quantum fluctuations at the universe’s birth were stretched out by a brief but spectacular cosmic growth spurt known as inflation. But some features in the maps don’t fit into the leading models of inflation. For example, the relatively even pattern of the CMB is marred by an unusually large cold region. Scientists have struggled to explain it, suggesting a number of ideas that require exotic physics or even evidence for a multiverse. A much simpler explanation is that the cold spot is caused by a giant void in the universe. The cosmos consists of a web of bright galaxies and clusters surrounded by dark pockets that contain little matter. Radiation loses energy when it crosses these empty regions, so a large void could cause a cold spot in our CMB maps. But most surveys haven’t looked at a wide enough region of the sky to be able to find such a void relatively close to Earth. One study that claimed to have discovered one in 2007 was later disputed. István Szapudi at the University of Hawaii in Honolulu and his colleagues analysed an all-sky survey made by NASA’s WISE satellite to conduct their own hunt for a giant void. In May, they reported finding one about 2.8 billion light years away, in the direction of the cold spot. It stretches some 1.8 billion light years across, making it about twice the size of the previous largest known void, says Szapudi. Now the team has studied the properties of the so-called supervoid, including its alignment with the cold spot and its apparent depth. A number of techniques all yielded similar results, which the team says bolsters the case linking the void to the cold spot (arxiv.org/abs/1406.3622). “This would be the simplest explanation requiring no exotic physics,” says Szapudi. He adds that similarly simple causes may lie at the heart of other CMB mysteries, such as temperature differences that seem to be aligned along a preferred direction, dubbed the “axis of evil”. Dragan Huterer at the University of Michigan in Ann Arbor questioned the 2007 claim, but he thinks Szapudi’s team makes a good case for their void. “This is a very exciting finding,” he says. Maggie McKee n Biggest hole in universe solves cosmic cold case –Get WISE to voids– “We could try to stimulate the region in a minimally conscious person to try to jolt them out of this state” For daily news stories, visit newscientist.com/news
