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Monkey brain signals used to recreate faces
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Brain signals used to recreate photos of faces
Black hole merger rattles the cosmos Leah Crane
they were orbiting one another. But this third pair of black holes tilts towards Earth in a different way from the other two, according to Shoemaker, allowing LIGO to see more about how each one spins. This view has revealed that they aren’t spinning in the same direction as their orbit. That means they’re probably spinning
THREE’S a party. For the third time, the LIGO collaboration has detected gravitational waves emanating from a pair of merging black holes – yielding clues about how these duos form and building up our catalogue of them. “The first one was a novelty. The second one was confirmation that the novelty of the first one “Spins, and particularly was not a fluke. The third one misaligned spins, will help is astrophysics,” says LIGO us figure out how pairs of spokesperson David Shoemaker merging black holes form” at the Massachusetts Institute of Technology (MIT). LIGO detects waveforms, in different directions or – far which are readouts of the ripples less likely – not spinning at all. in the fabric of space-time caused “Spins, and particularly by masses moving through it. The misaligned spins, will help us spins of merging black holes can figure out how these things are warp those waveforms, which are formed,” says Carl Rodriguez mostly produced by their orbits at MIT. Going beyond detection and eventual collision. to examining these objects’ The first event yielded too properties turns this into a “new little information to determine branch of astronomy”, he adds. the direction of each black hole’s Black hole binaries are either spin. The second provided a bit born together from a pair of more information, indicating orbiting stars, or form separately that each black hole was probably in a dense stellar cluster and later spinning in the same direction as drift together at its centre. In the 14 | NewScientist | 10 June 2017
PRECISION images of real faces have been recreated by monitoring the activity of certain cells in the brains of macaque monkeys as they looked at photographs of people. The study is the first to provide a full and simple explanation of how the brains of macaques – and by implication, humans – generate composite images of any face they see. “We’ve cracked the brain’s code for facial identity,” says Doris Tsao at –All in a spin– the California Institute of Technology. The brain has regions of specialised first case, the pair should rotate in face cells, which become active when a person sees a face. Tsao and her the same direction they orbit, as binary stars do. In the second, says colleague, Steven Le Chang, inserted electrodes into three patches of these Rodriguez, “they’re pointing in cells in macaques, enabling them to whatever directions they please”. LIGO’s second detection, a black record the activity of 205 neurons. The pair then showed three of hole binary discovered in 2015, these macaques 2000 images of seemed to be from black holes human faces. They discovered that born orbiting together. But this each of the face cells is tuned to view new pair, found on 4 January, may have formed independently. faces in slightly different ways – as if photographing a face from multiple At least one of the black holes angles at once. The combined signals seems to spin in a different from these cells encode 50 different direction to its orbit. The aspects of a face – for example, differences indicate that both shape, distance between eyes and formation scenarios can occur. skin texture. Because this new black hole When all these are combined, binary is about 3 billion light they give a clear composite image. years away – twice as far as the “The key is that even though there’s others we’ve detected – its an infinite number of faces, you can gravitational waves have to describe all of them with just these ripple through more space-time 50 dimensions,” says Tsao. before they reach Earth. That The researchers developed distance allows us to get greater algorithms from the face-cell feedback insight into potential deviations that enabled them to recreate from Einstein’s theory of general composite facial images from monkey relativity (Physical Review brain-cell activity (Cell, doi.org/b73v). Letters, doi.org/b73r). It is likely that memories of General relativity states that all familiar faces are held by a different gravitational waves should travel type of cell in the hippocampus. at the same speed – the speed of “Tsao’s work provides the first specific light. Because the waves seemed hypothesis for how the response of to do that in this case, even over such a huge distance, they backed face cells in the cortex can be utilised by cells in the hippocampus to form up Einstein’s cosmic rule. memories of individuals we’ve seen The research marks the start before,” says Ueli Rutishauser at the of an era of using gravitational Cedars-Sinai Medical Center in Los waves to study the cosmic kin of Angeles. Andy Coghlan n black hole binaries. n
sxs
Brain signals used to recreate photos of faces
Black hole merger rattles the cosmos Leah Crane
they were orbiting one another. But this third pair of black holes tilts towards Earth in a different way from the other two, according to Shoemaker, allowing LIGO to see more about how each one spins. This view has revealed that they aren’t spinning in the same direction as their orbit. That means they’re probably spinning
THREE’S a party. For the third time, the LIGO collaboration has detected gravitational waves emanating from a pair of merging black holes – yielding clues about how these duos form and building up our catalogue of them. “The first one was a novelty. The second one was confirmation that the novelty of the first one “Spins, and particularly was not a fluke. The third one misaligned spins, will help is astrophysics,” says LIGO us figure out how pairs of spokesperson David Shoemaker merging black holes form” at the Massachusetts Institute of Technology (MIT). LIGO detects waveforms, in different directions or – far which are readouts of the ripples less likely – not spinning at all. in the fabric of space-time caused “Spins, and particularly by masses moving through it. The misaligned spins, will help us spins of merging black holes can figure out how these things are warp those waveforms, which are formed,” says Carl Rodriguez mostly produced by their orbits at MIT. Going beyond detection and eventual collision. to examining these objects’ The first event yielded too properties turns this into a “new little information to determine branch of astronomy”, he adds. the direction of each black hole’s Black hole binaries are either spin. The second provided a bit born together from a pair of more information, indicating orbiting stars, or form separately that each black hole was probably in a dense stellar cluster and later spinning in the same direction as drift together at its centre. In the 14 | NewScientist | 10 June 2017
PRECISION images of real faces have been recreated by monitoring the activity of certain cells in the brains of macaque monkeys as they looked at photographs of people. The study is the first to provide a full and simple explanation of how the brains of macaques – and by implication, humans – generate composite images of any face they see. “We’ve cracked the brain’s code for facial identity,” says Doris Tsao at –All in a spin– the California Institute of Technology. The brain has regions of specialised first case, the pair should rotate in face cells, which become active when a person sees a face. Tsao and her the same direction they orbit, as binary stars do. In the second, says colleague, Steven Le Chang, inserted electrodes into three patches of these Rodriguez, “they’re pointing in cells in macaques, enabling them to whatever directions they please”. LIGO’s second detection, a black record the activity of 205 neurons. The pair then showed three of hole binary discovered in 2015, these macaques 2000 images of seemed to be from black holes human faces. They discovered that born orbiting together. But this each of the face cells is tuned to view new pair, found on 4 January, may have formed independently. faces in slightly different ways – as if photographing a face from multiple At least one of the black holes angles at once. The combined signals seems to spin in a different from these cells encode 50 different direction to its orbit. The aspects of a face – for example, differences indicate that both shape, distance between eyes and formation scenarios can occur. skin texture. Because this new black hole When all these are combined, binary is about 3 billion light they give a clear composite image. years away – twice as far as the “The key is that even though there’s others we’ve detected – its an infinite number of faces, you can gravitational waves have to describe all of them with just these ripple through more space-time 50 dimensions,” says Tsao. before they reach Earth. That The researchers developed distance allows us to get greater algorithms from the face-cell feedback insight into potential deviations that enabled them to recreate from Einstein’s theory of general composite facial images from monkey relativity (Physical Review brain-cell activity (Cell, doi.org/b73v). Letters, doi.org/b73r). It is likely that memories of General relativity states that all familiar faces are held by a different gravitational waves should travel type of cell in the hippocampus. at the same speed – the speed of “Tsao’s work provides the first specific light. Because the waves seemed hypothesis for how the response of to do that in this case, even over such a huge distance, they backed face cells in the cortex can be utilised by cells in the hippocampus to form up Einstein’s cosmic rule. memories of individuals we’ve seen The research marks the start before,” says Ueli Rutishauser at the of an era of using gravitational Cedars-Sinai Medical Center in Los waves to study the cosmic kin of Angeles. Andy Coghlan n black hole binaries. n