Imagine a couple of million years ago, a curious young alien from the planet Zantar — let's call him a grad student — lands on Earth, looks around and asks, "Who's the brainiest critter on this planet? Relative to body size, who's got the biggest brain?" The answer, back then, would not have been us. (Two million years ago, apes — even walking ones — had much smaller brains.) The brainiest weren't ancestral crows or parrots or magpies or ravens or elephants or colonies of ants or bees or termites. The Earthlings with the biggest brains back then were dolphins (and certain whales). The Zantarian grad student would have wanted to meet them. A visitor from Zantar and a dolphin check each other out. But had the grad student arrived earlier, dolphins wouldn't have been the champs, because evolution is always changing life. , at Emory University in Atlanta, has been studying fossilized brains. And looking back, she sees sudden spurts of brain growth in different animals. "[T]he most dramatic increase in brain-to-body ratio in dolphins and toothed whales occurred 35 million years ago," she tells Chris Impey, the astronomer and writer, in Talking About Life. Something happened to make their medium-sized brains bigger, Lori says, then bigger still. For 20 million years certain dolphin species kept their brains growing until — just as mysteriously as it started — about 15 million years ago, they stopped. Why? Had the dolphins answered some secret dolphin question? Figured out a puzzle? Adapted to an environmental change? Gotten tired? Hit a limit? What? Dolphin says, "Enough." ©2014 NPR

Keyword: Evolution; Intelligence
Link ID: 19131 - Posted: 01.15.2014

By Matt McGrath Environment correspondent, BBC News Taking substances to enhance the brain is more popular among amateur athletes than taking drugs to boost the body. Researchers in Germany found that 15% of recreational triathletes admitted to brain doping, using prescription medicines that increase attention. Some 13% of competitors reported using physical enhancers like steroids or human growth hormone. Brain doping is more popular say the scientists, because many of the substances aren't banned. The research has been published in the journal Plos One. Previous studies have shown that, among amateur competitors, the use of performance-enhancing substances is widespread. This new work used the responses of almost 3,000 triathletes taking part in events in Germany, to analyse the broader picture of physical and cognitive doping. Researchers believe that many so-called "smart drugs" are being widely used to enhance mental functions outside the patients groups they have been designed to help. They are also concerned that competitors in a variety of sports may be using these substances to gain an edge. In the study, participants were asked whether they had used physical or brain-enhancing substances in the past 12 months. Overall, 13% said they had taken drugs like EPO, steroids, or growth hormones. BBC © 2014

Keyword: Drug Abuse; Attention
Link ID: 19130 - Posted: 01.15.2014

Ask a group of people to describe the color of a sheet of paper, a cloud, or a glass of milk, and chances are they’ll all say “white.” But ask the same group to describe the smell of cinnamon, and you’ll likely get a potpourri of answers, ranging from “spicy” to “smoky” to “sweet,” and sometimes all three. When it comes to naming smells, humans struggle to find concise, universal terms. Indeed, scientists have long thought the ability was out of our reach. But a new study indicates that the inhabitants of a remote peninsula in Southeast Asia can depict smells as easily as the rest of us pick colors. The study concerns the Jahai, nomadic hunter-gatherers who live in the mountain rainforests along the border between Malaysia and Thailand. Smell is very important to this society. Odors are often evoked in illness, or medicine, for example, and it is one of the few cultures to have words devoted exclusively to smells. “For example, the term pʔus (pronounced ‘pa-oos’) describes the smell of old huts, day-old food, and cabbage,” says Asifa Majid, a psychologist at the Centre for Language Studies at Radboud University Nijmegen in the Netherlands. This suggests, she says, that the Jahai can isolate basic smell properties, much like we can isolate the color white from milk. To find out if the Jahai are better at naming smells than the rest of us, Majid and colleagues asked native Jahai speakers and native English speakers to describe 12 different odors: cinnamon, turpentine, lemon, smoke, chocolate, rose, paint thinner, banana, pineapple, gasoline, soap, and onion. The Jahai easily and consistently named the odors, whereas English speakers struggled, the team reports in the February issue of Cognition. © 2014 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste)
Link ID: 19129 - Posted: 01.14.2014

By Scott O. Lilienfeld and Hal Arkowitz “Just say no.” In 1982 First Lady Nancy Reagan uttered those three words in response to a schoolgirl who wanted to know what she should say if someone offered her drugs. The first lady's suggestion soon became the clarion call for the adolescent drug prevention movement in the 1980s and beyond. Since then, schools around the country have instituted programs designed to discourage alcohol and drug use among youth—most of them targeting older elementary schoolchildren and a few addressing adolescents. There is good reason for concern about youth substance abuse. A large U.S. survey conducted in 2012 by psychologist Lloyd D. Johnston and his colleagues at the University of Michigan revealed that fully 24 percent of 12th graders had engaged in binge drinking (defined as five or more drinks on one occasion) in the past two weeks. Moreover, 42 percent had consumed at least some alcohol in the past month, as had 11 percent of eighth graders and 28 percent of high school sophomores. In addition, 1 percent of 12th graders had tried methamphetamine, and almost 3 percent had used cocaine in the past year. In an attempt to reduce these figures, substance abuse prevention programs often educate pupils regarding the perils of drug use, teach students social skills to resist peer pressure to experiment, and help young people feel that saying no is socially acceptable. All the approaches seem sensible on the surface, so policy makers, teachers and parents typically assume they work. Yet it turns out that approaches involving social interaction work better than the ones emphasizing education. That finding may explain why the most popular prevention program has been found to be ineffective—and may even heighten the use of some substances among teens. © 2014 Scientific American,

Keyword: Drug Abuse
Link ID: 19128 - Posted: 01.14.2014

By RICHARD A. FRIEDMAN, M.D. “How the Federal Government Destroyed the Mental Illness Treatment System”: That subtitle is the opening shot across the bow in this jeremiad of a book by the psychiatrist Dr. E. Fuller Torrey. It could just as well have read: “How a group of well-intentioned, starry-eyed idealists made a hash of mental health care.” You could hardly blame them for trying, though. The care of people with serious mental illness was long a national disgrace. By the 1950s, slightly more than half a million psychiatric patients resided in overcrowded and underfunded state mental hospitals, often under appalling conditions. Related Coverage Enter a group of high-minded psychiatrists with a vision to “create a brave new world, a mentally healthy America,” in Dr. Torrey’s words. Armed with little more than optimism, they helped start the National Institute of Mental Health and set in motion an ambitious agenda for the next half-century: closing the state mental hospitals, initiating a federal takeover of the mental health system, and creating a nationwide network of community mental health centers. Reform was well underway when President John F. Kennedy endorsed this new era in mental health in a 1963 speech, calling for a “bold new approach” in which “reliance on the cold mercy of custodial isolation will be supplanted by the open warmth of community concern and capability.” Those were heady days in American psychiatry, when psychoanalysis and the mental hygiene movement held sway and promised to cure all manner of ills by early intervention and improving the social environment. In hindsight, the therapeutic zeal of these professionals was impressively naïve: They were certain that severely mentally ill patients in state hospitals — many living there for decades — would magically adjust to the community and do well with outpatient treatment. How wrong they proved to be. © 2014 The New York Times Company

Keyword: Schizophrenia
Link ID: 19127 - Posted: 01.14.2014

Training to improve cognitive abilities in older people lasted to some degree 10 years after the training program was completed, according to results of a randomized clinical trial supported by the National Institutes of Health. The findings showed training gains for aspects of cognition involved in the ability to think and learn, but researchers said memory training did not have an effect after 10 years. The report, from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, appears in the January 2014 issue of the Journal of the American Geriatrics Society. The project was funded by the National Institute on Aging (NIA) and the National Institute of Nursing Research (NINR), components of the NIH. “Previous data from this clinical trial demonstrated that the effects of the training lasted for five years,” said NIA Director Richard J. Hodes, M.D. “Now, these longer term results indicate that particular types of cognitive training can provide a lasting benefit a decade later. They suggest that we should continue to pursue cognitive training as an intervention that might help maintain the mental abilities of older people so that they may remain independent and in the community.” “ACTIVE is an important example of intervention research aimed at enabling older people to maintain their cognitive abilities as they age,” said NINR Director Patricia Grady, Ph.D. “The average age of the individuals who have been followed over the last 10 years is now 82. Given our nation’s aging population, this type of research is an increasingly high priority.”

Keyword: Alzheimers; Learning & Memory
Link ID: 19126 - Posted: 01.14.2014

By Megan Wiegand and Slate, Tips for beating the seasonal blues are as numerous as the winter night is long. Light boxes, touted to “uplift people’s spirits” and “improve mood and energy,” offer a New-Agey-seeming solution to propel us into the cold as if it’s the first beautiful day of spring. But can sitting in front of a light for a few minutes a day actually counteract the dreariest months? Yes, in many cases. Light-box therapy has been shown to alleviate symptoms in people who suffer from seasonal affective disorder, or SAD. Symptoms of this form of depression — they can include lost interest in beloved activities, overeating, loss of energy, disrupted sleep cycles and feelings of hopelessness or guilt — typically appear in late fall or early winter and dissipate in spring. Women are twice as likely as men to seek treatment for SAD, and those farther away from the equator are more likely to be diagnosed: About 11 percent of Mainers have a clinical SAD diagnosis, but only 2 percent of Floridians report the illness, according to Kathryn Roecklein, an assistant professor of psychology at the University of Pittsburgh. One tool doctors use to treat SAD is light-box therapy. Light boxes use bright white fluorescent bulbs (or sometimes blue light) that reproduce some wavelengths of the sun’s light. They contain filters to block harmful UV rays and come in various shapes, sizes, light types and price points. © 1996-2014 The Washington Post

Keyword: Depression; Biological Rhythms
Link ID: 19125 - Posted: 01.14.2014

By C. CLAIBORNE RAY Q. Why do I wake up at exactly the same time every night, without any stimulus? It has happened all my life, and it doesn’t even matter what time I went to bed. A. What you are experiencing is probably a normal period of relative alertness that happens in the middle of the night, said Dr. Carl W. Bazil, director of the division of epilepsy and sleep at NewYork-Presbyterian/Columbia University Medical Center. “Most people realize that there is a natural drowsiness midday, usually around lunchtime,” Dr. Bazil said. “This is why many fortunate cultures developed the siesta.” But the reverse normally happens at night. The two interludes are both part of the body’s circadian rhythm, which he said is “controlled by an internal clock but of course influenced by lots of external things,” like caffeine, light, exercise and stress. Dr. Bazil said it might also help those who wake up midsleep to know that “before the advent of electrical lighting, it was normal for people to go to bed at sundown, sleep for about four hours and arise during that natural alertness for a few hours before returning for a ‘second sleep.’ ” © 2014 The New York Times Company

Keyword: Biological Rhythms; Sleep
Link ID: 19124 - Posted: 01.14.2014

By MARIA KONNIKOVA SLEEP seems like a perfectly fine waste of time. Why would our bodies evolve to spend close to one-third of our lives completely out of it, when we could instead be doing something useful or exciting? Something that would, as an added bonus, be less likely to get us killed back when we were sleeping on the savanna? “Sleep is such a dangerous thing to do, when you’re out in the wild,” Maiken Nedergaard, a Danish biologist who has been leading research into sleep function at the University of Rochester’s medical school, told me. “It has to have a basic evolutional function. Otherwise it would have been eliminated.” We’ve known for some time that sleep is essential for forming and consolidating memories and that it plays a central role in the formation of new neuronal connections and the pruning of old ones. But that hardly seems enough to risk death-by-leopard-in-the-night. “If sleep was just to remember what you did yesterday, that wouldn’t be important enough,” Dr. Nedergaard explains. In a series of new studies, published this fall in the journal Science, the Nedergaard lab may at last be shedding light on just what it is that would be important enough. Sleep, it turns out, may play a crucial role in our brain’s physiological maintenance. As your body sleeps, your brain is quite actively playing the part of mental janitor: It’s clearing out all of the junk that has accumulated as a result of your daily thinking. Recall what happens to your body during exercise. You start off full of energy, but soon enough your breathing turns uneven, your muscles tire, and your stamina runs its course. What’s happening internally is that your body isn’t able to deliver oxygen quickly enough to each muscle that needs it and instead creates needed energy anaerobically. And while that process allows you to keep on going, a side effect is the accumulation of toxic byproducts in your muscle cells. Those byproducts are cleared out by the body’s lymphatic system, allowing you to resume normal function without any permanent damage. © 2014 The New York Times Company

Keyword: Sleep
Link ID: 19123 - Posted: 01.13.2014

Ian Sample, science correspondent A cup or two of coffee could boost the brain's ability to store long-term memories, researchers in the US claim. People who had a shot of caffeine after looking at a series of pictures were better at distinguishing them from similar images in tests the next day, the scientists found. The task gives a measure of how precisely information is stored in the brain, which helps with a process called pattern separation which can be crucial in everyday situations. If the effect is real, and some scientists are doubtful, then it would add memory enhancement to the growing list of benefits that moderate caffeine consumption seems to provide. Michael Yassa, a neuroscientist who led the study at Johns Hopkins University in Baltimore, said the ability to separate patterns was vital for discriminating between similar scenarios and experiences in life. "If you park in the same parking lot every day, the spot you choose can look the same as many others. But when you go and look for your car, you need to look for where you parked it today, not where you parked it yesterday," he said. Writing in the journal Nature Neuroscience, Yassa described how 44 volunteers who were not heavy caffeine consumers and had abstained for at least a day were shown a rapid sequence of pictures on a computer screen. The pictures included a huge range of items, such as a hammer, a chair, an apple, a seahorse, a rubber duck and a car. © 2014 Guardian News and Media Limited

Keyword: Learning & Memory; Drug Abuse
Link ID: 19122 - Posted: 01.13.2014

By Gary Stix The blood-brain barrier is the Berlin Wall of human anatomy and physiology Its closely packed cells shield neurons and the like from toxins and pathogens, while letting pass glucose and other essential chemicals for brain metabolism (caffeine?). For years, pharmaceutical companies and academic researchers have engaged in halting efforts to traverse this imposing blockade in order to deliver some of the big molecules that might potentially help slow the progression of devastating neurological diseases. Like would-be refugees from the former East Germany, many medications get snagged by border guards during the crossing—a molecular security force that either impedes or digests any invader. There have been many attempts to secure safe passage—deploying chemicals that make brain-barrier “endothelial” cells shrivel up, or wielding tiny catheters or minute bubbles that slip through minuscule breaches. Success has been mixed at best—none of these molecular cargo carriers have made their way as far as human trials. Roche, the Swiss-based drugmaker, reported in the Jan. 8 Neuron a bit of progress toward overcoming the lingering technical impediments. The study described a new technique that tricks one of the BBB’s natural checkpoints to let through an elaborately engineered drug that attacks the amyloid-beta protein fragments that may be the primary culprit inflicting the damage wrought by Alzheimer’s. The subterfuge involves the transferrin receptor, a docking site used to transport iron into the brain. Roche took a fragment of an antibody that binds the transferrin receptor and latched it onto another antibody that, once on the other side of the BBB, attaches to and then removes amyloid. © 2014 Scientific American

Keyword: Alzheimers
Link ID: 19121 - Posted: 01.13.2014

By CATHERINE SAINT LOUIS The standard treatment for people with moderate to severe obstructive sleep apnea is a mask worn at night that helps them breathe without interruption. The mask is unwieldy and uncomfortable, however; one study found that46 percent to 83 percent of patients with obstructive sleep apnea do not wear it diligently. Now scientists may have found an alternative, at least for some patients: a pacemaker-like device implanted in the chest that stimulates a nerve in the jaw, helping to keep part of the upper airway open. The device, called a neurostimulator, helped reduce breathing interruptions and raise blood oxygen levels in about two-thirds of sleep apnea patients participating in a trial, researchers reported on Wednesday in The New England Journal of Medicine. “This is a new paradigm of surgical treatment that seems to effectively control obstructive sleep apnea in selected patients,” said Dr. Sean M. Caples, a sleep specialist in the division of pulmonary and critical care medicine at Mayo Clinic in Rochester, Minn. “It’s very exciting.” Still, Dr. Caples, who was not involved in the new study, noted that “a third of patients were not improved when all was said and done,” even though they were chosen because they were seen as likely to benefit. The new trial was funded by the maker of the device, Inspire Medical Systems. At 22 sites internationally, in 126 patients, doctors surgically implanted a remote-controlled neurostimulator that, activated at night, sends regular electric impulses to a nerve inside the jaw. The impulses cause the tongue to move forward during inhalation, opening the airway. Copyright 2014 The New York Times Company

Keyword: Sleep
Link ID: 19120 - Posted: 01.11.2014

Tim Phillips, GlobalPost As we begin 2014, we still haven’t engaged in a conversation about gun control that brings both sides together. Polls indicate a country more or less divided over how to prevent another school shooting. And while legislation has been proposed to reign in the gun lobby, sales of guns have soared. This debate is not a new one in the United States, and while it intensifies with each tragic mass shooting, the conversation rarely advances. Frustration sets in as each new action causes the other side to dig in their heels even further. We wonder: Is there another way to frame this issue? For the last 20 years I have led an international organization that works in war torn countries to negotiate an end to conflict. In places like Northern Ireland, El Salvador, South Africa and the Balkans, groups once driven to violence to defend their beliefs have put down their weapons, sat down at a table, overcome their differences and negotiated. Moving beyond conflict is, indeed, possible. One dynamic I have observed present in all successful negotiations — which is missing from our current debate over gun control — is a recognition of the role of sacred values. Social scientists define sacred values as a set of values or principles that individuals and communities hold dear to their idea of right and wrong, that define who they are and help guide their daily lives. We first came to see the critical role played by sacred values in the 1990s in dealing with the bloody conflict in Northern Ireland in which thousands of people were killed. No one used the term sacred values back then, but we could see clearly that one of the reasons negotiations to end sectarian conflict between Catholics and Protestants in Ireland were failing was because they were not recognizing or respecting the deep differences in values, cultures and identities that each side held. © 2014 Salon Media Group, Inc.

Keyword: Aggression; Emotions
Link ID: 19119 - Posted: 01.11.2014

By NICHOLAS BAKALAR We know that smoking is bad for you — and that it ages you prematurely. Now a study provides photographic evidence for this claim. Scientists gathered health and lifestyle information on 79 pairs of identical adult twins who fit into one of three groups: a pair in which one was a smoker and the other had never smoked; a pair in which both were smokers; or a pair in which both were smokers but with at least a 5-year difference in the duration of their smoking habit. They photographed them and had independent judges rate the pictures side-by-side for wrinkles, crow’s feet, jowls, bags under the eyes, creases around the nose, lines around the lips and other evidence of aging skin. The differences in some other factors that can age skin prematurely — alcohol consumption, sunscreen use and perceived stress at work — were statistically insignificant between twin pairs. But the judges’ decisions on which twin looked older coincided almost perfectly with their smoking histories. “The purpose of this study was to offer scientific evidence that smoking changes not only longevity, but also quality of appearance,” said the senior author, Dr. Bahman Guyuron, chairman of the plastic surgery department at University Hospital, Case Medical Center in Cleveland. “It is harmful any way you look at it.” Copyright 2014 The New York Times Company

Keyword: Drug Abuse
Link ID: 19118 - Posted: 01.11.2014

By Katherine Harmon Courage Unless you’ve eaten sannakji, the Korean specialty of semi-live octopus, you might never have had a squirming octopus arm in your mouth. But you’ve most likely had a very similar experience. In fact, you’re probably having one right now. Octopus arms might seem strange and mysterious, but they are remarkably similar to the human tongue. Known as muscular hydrostats, both of these appendages can easily bend, extend and change shape (remember that time you had to stretch out your tongue to lick that last bit of chocolate pudding from the bottom of the cup?). Researchers are hoping a new interdisciplinary project to look at movement in the octopus arm and the human tongue will shed light on how both of these complex structures are activated. This, in turn, could help scientists understand neurological diseases that affect speech, such as Parkinson’s. “The human tongue is a very different muscular system than the rest of the human body,” Khalil Iskarous, an assistant professor of linguistics at the University of Southern California who is helping to lead the research, said in a prepared statement. “Our bodies are vertebrate mechanisms that operate by muscle working on bone to move. The tongue is in a different muscular family, much like an invertebrate. It’s entirely muscle—it’s muscle moving muscle.” Both move by compressing fluid in one section of a muscle, creating movement in another part. But we know little about exactly how that movement is initiated and so finely controlled. © 2014 Scientific American

Keyword: Movement Disorders
Link ID: 19117 - Posted: 01.11.2014

The battle over animal experimentation in Italy took a nasty turn this week when anonymous activists posted fliers showing photos, home addresses, and telephone numbers of scientists involved in animal research at the University of Milan and labeled them as "murderers." The leaflets, which appeared in the night of 6 to 7 January, triggered widespread condemnation in academic and political circles. The posters targeted physiologist Edgardo D'Angelo, parasitologist Claudio Genchi, pharmacologist Alberto Corsini, and Maura Francolini, a biologist. The texts say they are “guilty” of performing animal experiments; Corsini is said to "have tortured and killed animals for more than 30 years.” His flier ends with his phone number and the suggestion to "call this executioner and tell him what you think of him." Although the fliers didn't contain a specific call to violence, the implicit threat is unmistakable, Italian scientists say. Pro-Test Italia, an organization that seeks to defend and explain animal research, has likened the campaign to a witch hunt. “It's unacceptable that those who work for the good of science and public health are called murderers by someone who publicly incites violence against them,” says Dario Padovan, a biologist and president of Pro-Test Italia. Many politicians condemned the new tactic as well. "I wish to express my deepest sympathy and support to the researchers in Milan for the intimidation and threats they suffered," Italy's minister of education, universities and research, Maria Chiara Carrozza, tweeted yesterday. The University of Milan has filed a complaint and the city's police department has started an investigation. “We will strengthen our commitment to the defense of research as a tool to improve knowledge and care for sick people,” Gianluca Vago, the university's rector, told the newspaper Corriere della Sera. © 2014 American Association for the Advancement of Science

Keyword: Animal Rights
Link ID: 19116 - Posted: 01.11.2014

by Helen Thomson A drug for perfect pitch is just the start: mastering new skills could become easy if we can restore the brain's youthful ability to create new circuits WANNABE maestros, listen up. A mood-stabilising drug can help you achieve perfect pitch – the ability to identify any note you hear without inferring it from a reference note. Since this is a skill that is usually acquired only early in life, the discovery is the first evidence that it may be possible to revert the human brain to a childlike state, enabling us to treat disorders and unlock skills that are difficult, if not impossible, to acquire beyond a certain age. From bilingualism to sporting prowess, many abilities rely on neural circuits that are laid down by our early experiences. Until the age of 7 or so, the brain goes through several "critical periods" during which it can be radically changed by the environment. During these times, the brain is said to have increased plasticity. In order to take advantage of these critical periods, the brain needs to be stimulated appropriately so it lays down the neuronal circuitry needed for a particular ability. For example, young children with poor sight in one eye may develop lazy eye, or amblyopia. It can be treated by covering the better eye, forcing the child to use the lazy eye – but this strategy only works during the critical period. These windows of opportunity are fleeting, but now researchers are beginning to understand what closes them and how they might be reopened. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Hearing
Link ID: 19115 - Posted: 01.09.2014

By Stephen L. Macknik Hypoglycemia occurs when your blood sugar gets dangerously low, resulting in sweating, the feeling of weakness and dysphoria (the “don’t touch me” feeling you have when you’re sick and nauseous, possibly unconscious, as with the flu), and a variety of other symptoms. You basically go into a state similar to shock. The principal problem, however, arises from low blood sugar supply to the brain, resulting in impairment of function. It’s a common problem in diabetic non-compliance (not eating low-carbohydrate foods while diabetic), which is especially prevalent in the poor. SABRINA TAVERNISE, of The New York Times reported on a new study in the journal Health Affairs, by Seligman and colleagues of the University of California, San Francisco, in which they analyzed the prevalence of hypoglycemia in low income populations at risk for hypoglycemia, as a function of time since the patients’ households’ last pay day. They found that hypoglycemia increases at the end of a pay cycle in low-income diabetics. They thus concluded that low-income diabetic patients have low access to food at the end of the month, resulting in frank starvation and thus low blood sugar. I find this to be an unlikely scenario. It’s not that I don’t believe that low-income is tied to diabetes and hypoglycemia at the end of the pay cycle. I do believe it, and the Centers for Disease Control have determined that 8% of the population has diabetes, and that the burden is carried by low-income families. So I think the main effect, increased hypoglycemia in the poor at the end of their pay cycle, is correct (and Ms. Tavernise reports that experts in the field are happy with the methods, so I’m happy with them too as a non-expert in this field). © 2014 Scientific American

Keyword: Obesity
Link ID: 19114 - Posted: 01.09.2014

by Anil Ananthaswamy Next time you happen to be snorkelling near a coral reef, keep an eye out for mantis shrimp. In all likelihood, these crustaceans, which resemble small lobsters, will have spotted you: they scan their surroundings with rapid eye movements just like those of primates. Justin Marshall of the University of Queensland in Brisbane, Australia, and colleagues have been studying mantis shrimp for years, and it is how they use their eyes that interests Marshall. Their eyes are on stalks and can dart around. Humans use similar rapid eye movements, called saccades, to "acquire" or lock on to new objects, and to track them as they move. "It was not clear whether the shrimp eye movements were anything to do with acquiring objects, or just repositioning the eyes," Marshall says. To find out, the team placed mantis shrimp in a perspex tube inside an aquarium, and suddenly introduced a small coloured disc into their line of sight. A camera outside the aquarium filmed their eyes. The team found that the mantis shrimp's fovea – the part of the eye with the highest resolution – was using saccades to home in on the coloured disc. This sort of behaviour is normally found in animals like primates, says Marshall. The saccadic eye movements are extremely rapid. Human saccades can sweep through a field of view at a rate of 200-300 degrees per second. "[Mantis shrimp] are actually going up to twice that amount," says Marshall. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 19113 - Posted: 01.09.2014

By Partha Mitra Leonardo Da Vinci, in his Treatise on Painting (Trattato della Pittura), advises painters to pay particular attention to the motions of the mind, moti mentali. “The movement which is depicted must be appropriate to the mental state of the figure,” he advises; otherwise the figure will be considered twice dead: “dead because it is a depiction, and dead yet again in not exhibiting motion either of the mind or of the body.” Francesco Melzi, student and friend to Da Vinci, compiled the Treatise posthumously from fragmented notes left to him. The vivid portrayal of emotions in the paintings from Leonardo’s school shows that his students learned to read the moti mentali of their subjects in exquisite detail. Associating an emotional expression of the face with a “motion of the mind” was an astonishing insight by Da Vinci and a surprisingly modern metaphor. Today we correlate specific patterns of electrochemical dynamics (i.e. “motions”) of the central nervous system, with emotional feelings. Consciousness, the substrate for any emotional feeling, is itself a “motion of the mind,” an ephemeral state characterized by certain dynamical patterns of electrical activity. Even if all the neurons, their constituent parts and neuronal circuitry remained structurally the same, a change in the dynamics can mean the difference between consciousness and unconsciousness. But what kind of motion is it? What are the patterns of electrical activity that correspond to our subjective state of being conscious, and why? Can they be measured and quantified? This is not only a theoretical or philosophical question but also one that is of vital interest to the anesthesiologist trying to regulate the level of consciousness during surgery, or for the neurologist trying to differentiate between different states of consciousness following brain trauma. © 2014 Scientific American

Keyword: Consciousness
Link ID: 19112 - Posted: 01.08.2014