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by Lisa Grossman Marriage for all, no gay gene required. For same-sex couples in the US, 26 June was a landmark date: the Supreme Court legalised marriage between two men or two women in all 50 states. "[Same-sex couples] ask for equal dignity in the eyes of the law," wrote Associate Justice Anthony Kennedy in the decision. "The Constitution grants them that right." But one thing the decision didn't do was declare sexual orientation a "suspect class" under the law, which would have given it the same protection as race. One of the criteria for this classification is that the trait must be immutable – an argument that the gay rights movement has internalised under the banner of "we're born this way". But although there is some evidence that sexual orientation has a genetic component, most scientists agree that it's not that simple. "There's significant consensus in the scientific community that there's enough different interacting causes for sexual orientation that two different individuals can be gay for different combinations of reasons," says sexuality researcher Lisa Diamond at the University of Utah. "I think all the evidence suggests that we're born with an underlying capacity and then that capacity interacts with a whole bunch of other influences," she says – whether they be prenatal, genetic or environmental. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 21117 - Posted: 07.01.2015

By Dina Fine Maron The game is a contemporary of the original Nintendo but it still appeals to today’s teens and lab monkeys alike—which is a boon for neuroscientists. It offers no lifelike graphics. Nor does it boast a screen. Primate players—whether human or not—are simply required to pull levers and replicate patterns of flashing lights. Monkeys get a banana-flavored treat as a reward for good performance whereas kids get nickels. But the game's creators are not really in it for fun. It was created by toxicologists at the U.S. Food and Drug Administration in the 1980s to study how chronic exposure to marijuana smoke affects the brain. Players with trouble responding quickly and correctly to the game’s commands may have problems with short-term memory, attention or other cognitive issues. The game has since been adapted to address a different question: whether anesthetics used to knock pediatric patients unconscious during surgery and diagnostic tests could affect a youngster's long-term neural development and cognition. Despite 20 years’ worth of experiments in young rodents and monkeys, there have been few definitive answers. To date, numerous studies suggest that being put under with anesthesia early in life seems somehow related to future cognitive problems. But whether this association is causal or merely coincidence is unclear. Researchers do know that the young human brain is exceptionally sensitive. When kids are exposed to certain harmful chemicals in their formative years, that experience can fundamentally alter the brain’s architecture by misdirecting the physical connections between neurons or causing cell deaths. But unraveling whether anesthetics may fuel such long-term damage in humans remains a challenge. © 2015 Scientific American

Keyword: Development of the Brain; Sleep
Link ID: 21116 - Posted: 07.01.2015

by Colin Barras Men often lose their sex drive with age – and so, it seems do male Drosophila. Tsai-Feng Fu at the National Chi Nan University in Taiwan and his colleagues suspected that low levels of dopamine in the flies were to blame. Almost 300 neurones in the fruit-fly brain use dopamine. Comparing those linked to sexual function in elderly 40-day-old male flies and sprightly 10-day-old flies, Fu found the older neurones carried 10 times less dopamine. Boosting levels lengthened the time the older flies spent trying to mate. There are obviously big differences between a man's brain and that of a male Drosophila, but Fu says that the new results could provide a useful starting point for in-depth studies that may have clinical implications. For instance, that research might eventually identify ways to fine-tune dopamine levels in humans, perhaps to reverse age-related declines in sexual drive, or even to suppress an overactive libido. We already have therapies for treating male sexual dysfunction – notably the drug viagra. But probing the link between dopamine and sexual dysfunction is still important. For instance, dopamine-replacement therapy is one of the most effective treatments for Parkinson's disease – but the therapy can lead to harmful compulsive sexual behaviour. But Wendi Neckameyer at the Saint Louis University School of Medicine in Missouri isn't sure we should talk about potential implications for men just yet – it's enough to say that the researchers "have begun to tease out an incredibly complex neural circuit", she says. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 21115 - Posted: 07.01.2015

Hannah Devlin Science correspondent Two licensed drugs have been shown to halt brain degeneration in mice, raising the prospect of a rapid acceleration in the search for a medicine to beat Alzheimer’s disease. The results, presented on Tuesday at the Alzheimer’s Society annual research conference in Manchester, have been hailed as “hugely promising” because they involve medicines that are already known to be safe and well-tolerated in people – potentially cutting years from the timeline for drugs to reach patients. Speaking ahead of her presentation, Giovanna Mallucci, professor of clinical neuroscience at the University of Cambridge, said: “It’s really exciting. They’re licensed drugs. This means you’d do a straightforward basic clinical trial on a small group of patients because these are not new compounds, they’re known drugs.” The scientists have chosen not to name the two drugs, which are currently used for conditions unrelated to dementia, to avoid the possibility of patients seeking to use them ahead of any clinical trial to prove their efficacy. The findings build on a landmark study two years ago, showing that brain cell death could be halted in mice by switching off a faulty signal in the brain that stops new proteins being produced. However, the breakthrough relied on a compound that had severe physical side-effects including weight loss and diabetes, making it unsuitable for use in humans. The two drugs were identified after Mallucci’s team screened hundreds of licensed compounds in search for something safe that had the same protective effects on the brain. Clare Walton, research manager at the Alzheimer’s Society, said: “The new results are hugely promising because the drugs are already given to people and we know they’re safe.” © 2015 Guardian News and Media Limited

Keyword: Alzheimers
Link ID: 21114 - Posted: 07.01.2015

Moheb Costandi Different immune cells regulate pain sensitization in male and female mice, according to research published on 29 June in Nature Neuroscience1. The surprising biological divide may explain why some clinical trials of pain drugs have failed, and highlights shortcomings in the way that many researchers design their experiments. The immune system has important roles in chronic pain, with cells called microglia being key players. Microglia express a protein called brain-derived neurotrophic factor (BDNF) to signal to spinal-cord neurons. When injury or inflammation occurs, this signal sensitizes the body to pain, so that even light touch hurts. Robert Sorge, a psychologist at the University of Alabama in Birmingham, and his colleagues induced persistent pain and inflammation in healthy male and female mice by severing two of the three sciatic nerve branches in their hind paws. Seven days later, they injected the animals with one of three drugs that inhibit microglial function. They found that all three drugs reversed pain sensitization in the male animals, as had been previously reported. But the treatments had no effect on the females, even though the animals had displayed equivalent levels of pain. The researchers also genetically engineered mice in which the BDNF gene could be deleted in microglia at any time during the animals' lives. At first, these animals exhibited normal responses to a nerve injury. Killing the microglia one week later extinguished that hypersensitivity in the male animals, but not in the females. This confirmed that in males, hypersensitivity to pain depends on BDNF signals from microglia, but that in females it is mediated by some other mechanism. © 2015 Nature Publishing Group,

Keyword: Pain & Touch; Sexual Behavior
Link ID: 21113 - Posted: 06.30.2015

By Christopher Intagliata Two decades ago, Swiss researchers had women smell the tee shirts that various men had slept in for two nights. Turned out that if women liked the aroma of a particular shirt, the guy who’d worn it was likely to have genetically coded immunity that was unlike the woman’s. Well the effect isn't just limited to sweaty shirts. Turns out we all smell things a little differently—you pick up a note of cloves, say, where I smell something more soapy—and that too gives clues to our degree of genetic similarity. Researchers tried that test with 89 people—having them sniff a couple dozen samples, and label each one using terms like lemony, coconut, fishy and floral. And each volunteer classified the scents differently enough that the researchers could single them out in subsequent tests, based on what they called each subject’s "olfactory fingerprint." Researchers then repeated that sniff test on another 130 subjects. But this time they did a blood test, too, to figure out each person's HLA type—an immune factor that determines whether you'll reject someone's organ, for example. They found that people who perceived smells similarly also had similar HLA types. Study author Lavi Secundo, a neuroscientist at the Weizmann Institute of Science in Israel, says the smell test could have real-world applications. "For organ donation you can think of this method as a quick, maybe a quick and dirty, method to sift between the best and the rest." He and his colleagues say it might even eliminate the need for 30 percent of the HLA tests done today. The work appears in the Proceedings of the National Academy of Sciences. [Lavi Secundo et al, Individual olfactory perception reveals meaningful nonolfactory genetic information] © 2015 Scientific American

Keyword: Chemical Senses (Smell & Taste); Genes & Behavior
Link ID: 21112 - Posted: 06.30.2015

By Jan Hoffman Guinea pigs do not judge. They do not bully. They are characteristically amiable, social and oh-so-tactile. They tuck comfortably into child-size laps and err on the side of the seriously cute. When playing with guinea pigs at school, children with autism spectrum disorders are more eager to attend, display more interactive social behavior and become less anxious, according to a series of studies, the most recent of which was just published in Developmental Psychobiology. In previous studies, researchers in Australia captured these results by surveying parents and teachers or asking independent observers to analyze videotapes of the children playing. In the new report, however, the researchers analyzed physiological data pointing to the animals’ calming effect on the children. The children played with two guinea pigs in groups of three — one child who was on the spectrum and two typically developing peers. All 99 children in the study, ages 5 to 12, wore wrist bands that monitored their arousal levels, measuring electric charges that race through the skin. Arousal levels can suggest whether a subject is feeling anxious or excited. The first time that typically developing children played with the guinea pigs, they reported feeling happy and registered higher levels of arousal. The researchers speculate that the children were excited by the novelty of the animals. Children with autism spectrum disorders also reported feeling elated, but the wrist band measurements suggested their arousal levels had declined. The animals seem to have lowered the children’s stress, the researchers concluded. © 2015 The New York Times Company

Keyword: Autism
Link ID: 21111 - Posted: 06.30.2015

Henry Nicholls Andy Russell had entered the lecture hall late and stood at the back, listening to the close of a talk by Marta Manser, an evolutionary biologist at the University of Zurich who works on animal communication. Manser was explaining some basic concepts in linguistics to her audience, how humans use meaningless sounds or “phonemes” to generate a vast dictionary of meaningful words. In English, for instance, just 40 different phonemes can be resampled into a rich vocabulary of some 200,000 words. But, explained Manser, this linguistic trick of reorganising the meaningless to create new meaning had not been demonstrated in any non-human animal. This was back in 2012. Russell’s “Holy shit, man” excitement was because he was pretty sure he had evidence for phoneme structuring in the chestnut-crowned babbler, a bird he’s been studying in the semi-arid deserts of south-east Australia for almost a decade. After the talk, Russell (a behavioural ecologist at the University of Exeter) travelled to Zurich to present his evidence to Manser’s colleague Simon Townsend, whose research explores the links between animal communication systems and human language. The fruits of their collaboration are published today in PLoS Biology. One of Russell’s students Jodie Crane had been recording the calls of the chestnut-crowned babbler for her PhD. The PLoS Biology paper focuses on two of these calls, which appear to be made up of two identical elements, just arranged in a different way. © 2015 Guardian News and Media Limited

Keyword: Language; Evolution
Link ID: 21110 - Posted: 06.30.2015

By Ariana Eunjung Cha One of the most heartbreaking things about Alzheimer's is that it has been impossible for doctors to predict who will get it before symptoms begin. And without early detection, researchers say, a treatment or cure may be impossible. Governments, drug companies and private foundations have poured huge amounts of money into trying to come up with novel ways to detect risk through cutting-edge technologies ranging from brain imaging, protein analysis of cerebrospinal fluid and DNA profiling. Now a new study, published in the journal Neurology, shows that perhaps something more old-fashioned could be the answer: a memory test. The researchers tracked 2,125 participants in four Chicago neighborhoods for 18 years, giving them tests of memory and thinking every three years. They found that those who scored lowest on the tests during the first year were 10 times more likely to be diagnosed with Alzheimer's down the road -- indicating that cognitive impairment may be affecting the brain "substantially earlier than previously established," the researchers wrote.

Keyword: Alzheimers; Learning & Memory
Link ID: 21109 - Posted: 06.30.2015

Allison Aubrey Bite into that bread before your main meal, and you'll spike your blood sugar and amp up your appetite. Waiting until the end of your dinner to nosh on bread can blunt those effects. Bite into that bread before your main meal, and you'll spike your blood sugar and amp up your appetite. Waiting until the end of your dinner to nosh on bread can blunt those effects. iStockphoto Ah, the bread basket. You sit down for a nice meal out, and there it appears: piping hot, giving off a waft of yeasty divinity. There's a reason this age-old tradition prevails. Even in the era of paleo and gluten-free, there are still hordes of us who will gladly nosh on crusty, chewy, soul-warming bread. But the downside may be more than just some extra calories. Turns out, eating all those carbs before a meal can amp up our appetites and spike our blood sugar. "The worst situation is having refined carbohydrates on an empty stomach, because there's nothing to slow down the digestion of that carbohydrate into sugar," explains David Ludwig, director of the Optimal Weight for Life Clinic at Boston Children's Hospital. © 2015 NPR

Keyword: Obesity
Link ID: 21108 - Posted: 06.30.2015

Emma Bowman In a small, sparse makeshift lab, Melissa Malzkuhn practices her range of motion in a black, full-body unitard dotted with light-reflecting nodes. She's strapped on a motion capture, or mocap, suit. Infrared cameras that line the room will capture her movement and translate it into a 3-D character, or avatar, on a computer. But she's not making a Disney animated film. Three-dimensional motion capture has developed quickly in the last few years, most notably as a Hollywood production tool for computer animation in films like Planet of the Apes and Avatar. Behind the scenes though, leaders in the deaf community are taking on the technology to create and improve bilingual learning tools in American Sign Language. Malzkuhn has suited up to record a simple nursery rhyme. Being deaf herself, she spoke with NPR through an interpreter. "I know in English there's just a wealth of nursery rhymes available, but we really don't see as much in ASL," she says. "So we're gonna be doing some original work here in developing nursery rhymes." That's because sound-based rhymes don't cross over well into the visual language of ASL. Malzkuhn heads the Motion Light Lab, or ML2. It's the newest hub of the National Science Foundation Science of Learning Center, Visual Language and Visual Learning (VL2) at Gallaudet University, the premier school for deaf and hard of hearing students. © 2015 NPR

Keyword: Language
Link ID: 21107 - Posted: 06.29.2015

By Sunnie Huang, CBC News The story of a Newfoundland man who was struck by a moose but doesn't remember it is not just a curious tale of luck. It also highlights the complex underpinnings of human memory, a neuroscience expert says. Stephen Bromley, from Conche, N.L., struck a moose with his car on Monday, but said he had no recollection it, even days after the collision. It's not the first time that something was amiss about human memory after a moose encounter. hi-moose-car-2012 Michelle Higgins said the roof of her car was peeled back "like a sardine can" after she struck a moose. Another Newfoundlander drove about 40 kilometres with her car's roof peeled back "like a sardine can" after crashing into a moose in 2012. Three years later, she said she still can't recall the incident. The blackout doesn't surprise Scott Watter, a McMaster University professor who specializes in neuroscience, psychology and behaviour. "They are lucky in that sense, but it doesn't seem like a thing that breaks the rules of everything we know about how brains work," he told CBC News. People who sustain head trauma often have poor memory of the event, especially when tested on specific details, Watter said. Also, the more severe the injury gets, the further back the memory loss extends, Watter said. The system at the heart of our memory is a seahorse-shaped section of the brain called the hippocampus, Watter explained. It's responsible for linking different parts of human experience to form a coherent memory. In the most severe — but rare — cases of hippocampus damage, the person can no longer create or retain new memory, as seen in Christopher Nolan's 2000 box office hit Memento. ©2015 CBC/Radio-Canada.

Keyword: Learning & Memory
Link ID: 21106 - Posted: 06.29.2015

Vaughan Bell Marketing has discovered neuroscience and the shiny new product has plenty of style but very little substance. “Neuromarketing” is lighting up the eyes of advertising executives and lightening the wallets of public relations companies. It promises to target the unconscious desires of consumers, which are supposedly revealed by measuring the brain. The more successful agencies have some of the world’s biggest brands on their books and these mega-corporations are happy to trumpet their use of brain science in targeting their key markets. The holy grail of neuromarketing is to predict which ads will lead to most sales before they’ve been released but the reality is a mixture of bad science, bullshit and hope. First, it’s important to realise that the concept of neuroscience is used in different ways in marketing. Sometimes, it’s just an empty ploy aimed at consumers – the equivalent of putting a bikini-clad body next to your product for people who believe they’re above the bikini ploy. A recent Porsche advert apparently showed a neuroscience experiment suggesting that the brain reacts in a similar way to driving their car and flying a fighter jet, but it was all glitter and no gold. The images were computer-generated, the measurements impossible, and the scientist an actor. In complete contrast, neuromarketing is also a serious research area. This is a scientifically sound, genuinely interesting field in cognitive science, where the response to products and consumer decision-making is understood on the level of body and mind. This might involve looking at how familiar brand logos engage the memory systems in the brain, or examining whether the direction of eye gaze of people in ads affects how attention-grabbing they are, or testing whether the brain’s electrical activity varies when watching subtly different ads. Like most of cognitive neuroscience, the studies are abstract, ultra-focused and a long way from everyday experience. © 2015 Guardian News and Media Limited

Keyword: Emotions
Link ID: 21105 - Posted: 06.29.2015

Amy Standen A doctor I interviewed for this story told me something that stuck with me. He said for every person with dementia he treats, he finds himself caring for two patients. That's how hard it can be to be a caregiver for someone with dementia. The doctor is Bruce Miller. He directs the Memory and Aging Center at the University of California, San Francisco. According to Miller, 50 percent of caregivers develop a major depressive illness because of the caregiving. "The caregiver is so overburdened that they don't know what to do next," he says. "This adds a huge burden to the medical system." This burden is going increase dramatically in the coming decade. By 2025, 7 million Americans will have Alzheimer's disease, according to one recent estimate. Millions more will suffer from other types of dementia. Together these diseases may become the most expensive segment of the so-called "silver tsunami" — 80 million baby boomers who are getting older and needing more medical care. The cost of caring for Alzheimer's patients alone is expected to triple by 2050, to more than $1 trillion a year. So UCSF, along with the University of Nebraska Medical Center, is beginning a $10 million study funded by the federal Centers for Medicare & Medicaid Innovation. Researchers plan to develop a dementia "ecosystem," which aims to reduce the cost of caring for the growing number of dementia patients and to ease the strain on caregivers. © 2015 NPR

Keyword: Alzheimers
Link ID: 21104 - Posted: 06.29.2015

by Clare Wilson Do you dream of where you'd like to go tomorrow? It looks like rats do. When the animals are shown a food treat at the end of a path they cannot access and then take a nap, the neurons representing that route in their brains fire as they sleep – as if they are dreaming about running down the corridor to grab the grub. "It's like looking at a holiday brochure for Greece the day before you go – that night you might dream about the pictures," says Hugo Spiers of University College London. Like people, rats store mental maps of the world in their hippocampi, two curved structures on either side of the brain. Putting electrodes into rats' brains as they explore their environment has shown that different places are recorded and remembered by different combinations of hippocampal neurons firing together. These "place cells" fire not only when a rat is in a certain location, but also when it sleeps, as if it is dreaming about where it has been in the past. Spiers's team wondered whether this activity during sleep might also reflect where a rat wants to go in future. They placed four rats at the bottom of a T-shaped pathway, with entry to the top bar of the T blocked by a grille. Food was placed at the end of one arm, in a position visible to the animals. Next they encouraged the rats to sleep in a cosy nest and recorded their hippocampus activity with about 50 electrodes each as they rested. Finally they put the rats back into the maze, but now with the grille and the treat removed. © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 21103 - Posted: 06.27.2015

Sharon Darwish Bottlenose dolphins have an average brain mass of 1.6 kg, slightly greater than that of humans, and about four times the size of chimpanzee brains. Although you couldn’t really imagine a dolphin writing poetry, dolphins demonstrate high levels of intelligence and social behaviour. For example, they display mirror self-recognition, as well as an understanding of symbol-based communication systems. Research into the differing brain sizes and intellectual capabilities within the animal kingdom is fascinating. Why have some species evolved to be more intelligent than others? Does brain size affect cognitive ability? Some studies say yes, but some insist otherwise. It really depends which species we are talking about. In humans, for example, larger brains do not indicate higher intelligence – otherwise Einstein, who had an average-sized brain, may have not been quite as successful in his career. (Yes, that link was to a 23-pager on the analysis of Einstein’s brain. It makes for great bedtime reading.) Most neuroscientists now believe that it is the structure of the brain on a cellular and molecular level that determines its computational capacity. Within certain animal species however, a larger brain offers evolutionary advantage. For example, large-brained female guppies are better survivors and demonstrate greater cognitive strengths than their smaller-brained counterparts. © 2015 Guardian News and Media Limited

Keyword: Development of the Brain; Genes & Behavior
Link ID: 21102 - Posted: 06.27.2015

By Bret Stetka Plenty of us have known a dog on Prozac. We have also witnessed the eye rolls that come with the mention of canine psychiatry. Doting pet owners—myself included—ascribe all kinds of questionable psychological ills to our pawed companions. But in fact, the science suggests that numerous nonhuman species do suffer from psychiatric symptoms. Birds obsess; horses on occasion get pathologically compulsive; dolphins and whales, especially those in captivity, self-mutilate. And that thing when your dog woefully watches you pull out of the driveway from the window—that might be DSM-certified separation anxiety. “Every animal with a mind has the capacity to lose hold of it from time to time,” wrote science historian and author Laurel Braitman in her 2014 book Animal Madness. But at least one mental malady, while common in humans, seems to have spared other animals: schizophrenia, which affects an estimated 0.4 to 1 percent of adults. Although animal models of psychosis exist in laboratories, and odd behavior has been observed in creatures confined to cages, most experts agree that psychosis has not typically been seen in other species, whereas depression, obsessive-compulsive disorder and anxiety traits have been reported in many nonhuman species. This raises the question of why such a potentially devastating, often lethal disease is still hanging around plaguing humanity. We know from an abundance of recent research that schizophrenia is heavily genetic in origin. One would think that natural selection would have eliminated the genes that predispose to psychosis. A study published earlier this year in Molecular Biology and Evolution provides clues as to how the potential for schizophrenia may have arisen in the human brain and, in doing so, suggests possible treatment targets. It turns out that psychosis may be an unfortunate cost of having a big brain that is capable of complex cognition. © 2015 Scientific American

Keyword: Schizophrenia
Link ID: 21101 - Posted: 06.27.2015

Matthew C Keller & Peter M Visscher Epidemiological studies and anecdotal evidence show overlap between psychiatric disorders and creativity, but why? A new study uses genome-wide association data from schizophrenia and bipolar disorder to show that genetics are part of the explanation. Thinkers contemplating the human condition have long associated creativity with psychiatric illness—the 'mad genius' archetype. According to Aristotle, “no great genius was without a mixture of insanity.” And there are the oft-repeated anecdotes: the psychotic breaks of Vincent van Gogh and John Nash, the manic and depressive episodes of Virginia Woolf and Ernest Hemingway. There is, in fact, some empirical evidence that the psychological factors underlying psychiatric disorders are linked to increased creativity. Unaffected relatives of those with bipolar disorder (BD) have greater creativity1 and are over-represented in creative professions2, and similar findings have been reported for schizophrenia (SCZ)2, 3. What these studies have not shown is whether this overlap is a result of genetic variation that influences both creativity and BD/SCZ or whether some environmental factor explains the association. For example, highly unstructured rearing environments might contribute to both creativity and risk of the disorders. Understanding whether shared gene variants are responsible for the overlap is important. It can help to elucidate the biological underpinnings of these disorders and shine light on the puzzle of why psychiatric diseases persist in the population. Power et al.4, in work reported in this issue of Nature Neuroscience, asked whether creativity and psychiatric disorders might be associated through common variation in the genome. They used a large discovery sample of 86,292 adults from Iceland and four replication samples totaling over 27,000 adults from Sweden and the Netherlands. All had genome-wide SNP genotyping and their professions were known. None of them knowingly suffered from a psychiatric illness. About 1% of them were artists, including actors, dancers, musicians and writers. © 2015 Macmillan Publishers Limited

Keyword: Schizophrenia; Genes & Behavior
Link ID: 21100 - Posted: 06.27.2015

By GARY MARCUS SCIENCE has a poor track record when it comes to comparing our brains to the technology of the day. Descartes thought that the brain was a kind of hydraulic pump, propelling the spirits of the nervous system through the body. Freud compared the brain to a steam engine. The neuroscientist Karl Pribram likened it to a holographic storage device. Many neuroscientists today would add to this list of failed comparisons the idea that the brain is a computer — just another analogy without a lot of substance. Some of them actively deny that there is much useful in the idea; most simply ignore it. Often, when scientists resist the idea of the brain as a computer, they have a particular target in mind, which you might call the serial, stored-program machine. Here, a program (or “app”) is loaded into a computer’s memory, and an algorithm, or recipe, is executed step by step. (Calculate this, then calculate that, then compare what you found in the first step with what you found in the second, etc.) But humans don’t download apps to their brains, the critics note, and the brain’s nerve cells are too slow and variable to be a good match for the transistors and logic gates that we use in modern computers. If the brain is not a serial algorithm-crunching machine, though, what is it? A lot of neuroscientists are inclined to disregard the big picture, focusing instead on understanding narrow, measurable phenomena (like the mechanics of how calcium ions are trafficked through a single neuron), without addressing the larger conceptual question of what it is that the brain does. This approach is misguided. Too many scientists have given up on the computer analogy, and far too little has been offered in its place. In my view, the analogy is due for a rethink. To begin with, all the standard arguments about why the brain might not be a computer are pretty weak. Take the argument that “brains are parallel, but computers are serial.” Critics are right to note that virtually every time a human does anything, many different parts of the brain are engaged; that’s parallel, not serial. © 2015 The New York Times Company

Keyword: Brain imaging
Link ID: 21099 - Posted: 06.27.2015

By Sarah Lewin Evolutionary biologists have long wondered why the eardrum—the membrane that relays sound waves to the inner ear—looks in humans and other mammals remarkably like the one in reptiles and birds. Did the membrane and therefore the ability to hear in these groups evolve from a common ancestor? Or did the auditory systems evolve independently to perform the same function, a phenomenon called convergent evolution? A recent set of experiments performed at the University of Tokyo and the RIKEN Evolutionary Morphology Laboratory in Japan resolves the issue. When the scientists genetically inhibited lower jaw development in both fetal mice and chickens, the mice formed neither eardrums nor ear canals. In contrast, the birds grew two upper jaws, from which two sets of eardrums and ear canals sprouted. The results, published in Nature Communications, confirm that the middle ear grows out of the lower jaw in mammals but emerges from the upper jaw in birds—all supporting the hypothesis that the similar anatomy evolved independently in mammals and in reptiles and birds. (Scientific American is part of Springer Nature.) Fossils of auditory bones had supported this conclusion as well, but eardrums do not fossilize and so could not be examined directly. © 2015 Scientific American

Keyword: Hearing; Evolution
Link ID: 21098 - Posted: 06.27.2015