Chapter 16. None
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When we move our head, the whole visual world moves across our eyes. Yet we can still make out a bee buzzing by or a hawk flying overhead, thanks to unique cells in the eye called object motion sensors. A new study on mice helps explain how these cells do their job, and may bring scientists closer to understanding how complex circuits are formed throughout the nervous system. The study was funded by the National Institutes of Health, and was published online in Nature. “Understanding how neurons are wired together to form circuits in the eye is fundamental for advancing potential new therapies for blinding eye diseases,” said Paul A. Sieving, M.D., Ph.D., director of NIH’s National Eye Institute (NEI). “Research aimed at regenerating photoreceptors, for example, is enriched by efforts to understand the circuitry in the eye.” Object motion sensors are one of about 30 different types of retinal ganglion cells (RGCs) in the retina, the light-sensitive tissue at the back of the eye. These cells are unique because they fire only when the timing of a small object’s movement differs from that of the background; they are silent when the object and the background move in sync. Researchers believe this is critical to our ability to see small objects moving against a backdrop of complex motion. The cells in the retina are wired up like an electrical circuit. Vision begins with photoreceptors, cells that detect light entering the eye and convert it into electrical signals. Middleman neurons, called interneurons, shuttle signals from photoreceptors to the RGCs. And each RGC sends the output visual information deeper into the brain for processing. This all takes place within fractions of a second, so the scientists were surprised to discover that before it reaches object motion sensors, visual information about object motion takes a detour through a unique type of interneuron. Their results represent an ongoing effort by scientists to map out complex circuits of the nervous system.
Link ID: 21368 - Posted: 09.01.2015
By EREZ YOELI and DAVID RAND Recently, three young American men and a British businessman thwarted a gunman’s attack on a French passenger train, acting within seconds and at enormous personal risk. When interviewed afterward, they stressed the unthinking nature of their actions. “It was just gut instinct,” said one, in a characteristic remark. “It wasn’t really a conscious decision.” This turns out to be typical of heroes. Last year, one of us, Professor Rand, together with his colleague Ziv Epstein, conducted an analysis of recipients of the Carnegie Medal for heroism, which is awarded to those who risk their lives for others. After collecting interviews given by 51 recipients and evaluating the transcripts, we found that the heroes overwhelming described their actions as fast and intuitive, and virtually never as carefully reasoned. This was true even in cases where the heroes had sufficient time to stop and think. Christine Marty, a college student who rescued a 69-year-old woman trapped in a car during a flash flood, said she was grateful that she didn’t take the time to reflect: “I’m thankful I was able to act and not think about it.” We found almost no examples of heroes whose first impulse was for self-preservation but who overcame that impulse with a conscious, rational decision to help. It is striking that our brute instincts, rather than our celebrated higher cognitive faculties, are what lead to such moral acts. But why would anyone ever develop such potentially fatal instincts? One possible explanation is that in most everyday situations, helping others pays off in the long run. You buy lunch for a friend or pitch in to help a colleague meet a tight deadline, and you find yourself repaid in kind, or even more, down the road. So it’s beneficial to develop a reflex to help — especially because the cost to you is usually quite small. © 2015 The New York Times Company
Link ID: 21365 - Posted: 08.31.2015
Depressed people who display "risky behaviour", agitation and impulsivity are at least 50% more likely to attempt suicide, a study has found. Research by the European College of Neuropsychopharmacology (ECNP) concluded that the behaviour patterns "precede many suicide attempts". The study said effective prevention measures were "urgently needed". The World Health Organisation estimates that there were more than 800,000 suicides worldwide in 2012. The ECNP study evaluated 2,811 patients suffering from depression, of whom 628 had previously attempted suicide. Researchers "looked especially at the characteristics and behaviours of those who had attempted suicide", and found that "certain patterns recur" before attempts. They said the risk of an attempt was "at least 50% higher" if a depressed patient displayed: "risky behaviour" such as reckless driving or promiscuous behaviour "psychomotor agitation" such as pacing around rooms or wringing their hands impulsivity - defined by the researchers as acting with "little or no forethought, reflection, or consideration of the consequences" Dr Dina Popovic, one of the report's authors, added: "We found that 'depressive mixed states' often preceded suicide attempts. "A depressive mixed state is where a patient is depressed, but also has symptoms of 'excitation', or mania." © 2015 BBC.
Link ID: 21364 - Posted: 08.31.2015
By Lily Hay Newman Mental health issues manifest in a number of ways, and they're not all behavioral. Increasingly, scientists are using speech analysis software to detect subtle changes in voice acoustics and patterns to detect or even predict potentially problematic conditions. A study published Wednesday in NPG-Schizophrenia by researchers at Columbia University Medical Center, the New York State Psychiatric Institute, and IBM's T. J. Watson Research Center found that digital speech analysis correctly predicted whether 34 youths at risk for mental illness (11 female, 23 male) would develop psychosis within 2.5 years. The system, which evaluated the study participants quarterly, correctly predicted all of their outcomes; five became psychotic. The algorithm evaluated transcripts for predictive "semantic and syntactic features" like coherence and phrase length. "These speech features predicted later psychosis development with 100% accuracy, outperforming classification from clinical interviews," the researchers wrote. Clinicians are able to accurately categorize patients as "at-risk," but within that subpopulation it is difficult to determine who will actually experience psychosis and potentially develop schizophrenia. If voice recognition software can help identify these individuals, they may be able to receive more effective care. "Computerized analysis of complex human behaviors such as speech may present an opportunity to move psychiatry beyond reliance on self-report and clinical observation toward more objective measures of health and illness in the individual patient," the researchers wrote. © 2015 The Slate Group LLC.
Link ID: 21362 - Posted: 08.31.2015
By GREGORY COWLES Oliver Sacks, the neurologist and acclaimed author who explored some of the brain’s strangest pathways in best-selling case histories like “The Man Who Mistook His Wife for a Hat,” using his patients’ disorders as starting points for eloquent meditations on consciousness and the human condition, died on Sunday at his home in Manhattan. He was 82. The cause was cancer, said Kate Edgar, his longtime personal assistant. Dr. Sacks announced in February, in an Op-Ed essay in The New York Times, that an earlier melanoma in his eye had spread to his liver and that he was in the late stages of terminal cancer. As a medical doctor and a writer, Dr. Sacks achieved a level of popular renown rare among scientists. More than a million copies of his books are in print in the United States, his work was adapted for film and stage, and he received about 10,000 letters a year. (“I invariably reply to people under 10, over 90 or in prison,” he once said.) Dr. Sacks variously described his books and essays as case histories, pathographies, clinical tales or “neurological novels.” His subjects included Madeleine J., a blind woman who perceived her hands only as useless “lumps of dough”; Jimmie G., a submarine radio operator whose amnesia stranded him for more than three decades in 1945; and Dr. P. — the man who mistook his wife for a hat — whose brain lost the ability to decipher what his eyes were seeing. Describing his patients’ struggles and sometimes uncanny gifts, Dr. Sacks helped introduce syndromes like Tourette’s or Asperger’s to a general audience. But he illuminated their characters as much as their conditions; he humanized and demystified them. © 2015 The New York Times Company
Link ID: 21361 - Posted: 08.31.2015
An experimental gene therapy reduces the rate at which nerve cells in the brains of Alzheimer’s patients degenerate and die, according to new results from a small clinical trial, published in the current issue of the journal JAMA Neurology. Targeted injection of the Nerve Growth Factor gene into the patients’ brains rescued dying cells around the injection site, enhancing their growth and inducing them to sprout new fibres. In some cases, these beneficial effects persisted for 10 years after the therapy was first delivered. Alzheimer’s is the world’s leading form of dementia, affecting an estimated 47 million people worldwide. This figure is predicted to almost double every 20 years, with much of this increase is likely to be in the developing world. And despite the huge amounts of time, effort, and money devoted to developing an effective cure, the vast majority of new drugs have failed in clinical trials. The new results are preliminary findings from the very first human trials designed to test the potential benefits of nerve growth factor (NGF) gene therapy for Alzheimer’s patients. NGF was discovered in the 1940s by Rita Levi-Montalcini, who convincingly demonstrated that the small protein promotes the survival of certain sub-types of sensory neurons during development of the nervous system. Since then, others have shown that it also promotes the survival of acetylcholine-producing cells in the basal forebrain, which die off in Alzheimer’s. © 2015 Guardian News and Media Limited
By Claire Asher If you stuck to Aesop’s fables, you might think of all ants as the ancient storyteller described them—industrious, hard-working, and always preparing for a rainy day. But not every ant has the same personality, according to a new study. Some colonies are full of adventurous risk-takers, whereas others are less aggressive about foraging for food and exploring the great outdoors. Researchers say that these group “personality types” are linked to food-collecting strategies, and they could alter our understanding of how social insects behave. Personality—consistent patterns of individual behavior—was once considered a uniquely human trait. But studies since the 1990s have shown that animals from great tits to octopuses exhibit “personality.” Even insects have personalities. Groups of cockroaches have consistently shy and bold members, whereas damselflies have shown differences in risk tolerance that stay the same from grubhood to adulthood. To determine how group behavior might vary between ant colonies, a team of researchers led by Raphaël Boulay, an entomologist at the University of Tours in France, tested the insects in a controlled laboratory environment. They collected 27 colonies of the funnel ant (Aphaenogaster senilis) and had queens rear new workers in the lab. This meant that all ants in the experiment were young and inexperienced—a clean slate to test for personality. The researchers then observed how each colony foraged for food and explored new environments. They counted the number of ants foraging, exploring, or hiding during set periods of time, and then compared the numbers to measure the boldness, adventurousness, and foraging efforts of each group. © 2015 American Association for the Advancement of Science
Link ID: 21358 - Posted: 08.29.2015
Raiding the fridge or downing glasses of water after a night of heavy drinking won't improve your sore head the next day, Dutch research suggests. Instead, a study concluded, the only way to prevent a hangover is to drink less alcohol. More than 800 students were asked how they tried to relieve hangover symptoms, but neither food nor water was found to have any positive effect. The findings are being presented at a conference in Amsterdam. A team of international researchers from the Netherlands and Canada surveyed students' drinking habits to find out whether hangovers could be eased or if some people were immune to them. Among 826 Dutch students, 54% ate food after drinking alcohol, including fatty food and heavy breakfasts, in the hope of staving off a hangover. With the same aim, more than two-thirds drank water while drinking alcohol and more than half drank water before going to bed. Although these groups showed a slight improvement in how they felt compared with those who hadn't drunk water, there was no real difference in the severity of their hangovers. Previous research suggests that about 25% of drinkers claim never to get hangovers. So the researchers questioned 789 Canadian students about their drinking in the previous month and the hangovers they experienced, finding that those who didn't get a hangover simply consumed "too little alcohol to develop a hangover in the first place". Of those students who drank heavily, with an estimated blood alcohol concentration of more than 0.2%, almost no-one was immune to hangovers. © 2015 BBC.
Keyword: Drug Abuse
Link ID: 21356 - Posted: 08.29.2015
By BENEDICT CAREY The past several years have been bruising ones for the credibility of the social sciences. A star social psychologist was caught fabricating data, leading to more than 50 retracted papers. A top journal published a study supporting the existence of ESP that was widely criticized. The journal Science pulled a political science paper on the effect of gay canvassers on voters’ behavior because of concerns about faked data. Now, a painstaking yearslong effort to reproduce 100 studies published in three leading psychology journals has found that more than half of the findings did not hold up when retested. The analysis was done by research psychologists, many of whom volunteered their time to double-check what they considered important work. Their conclusions, reported Thursday in the journal Science, have confirmed the worst fears of scientists who have long worried that the field needed a strong correction. The vetted studies were considered part of the core knowledge by which scientists understand the dynamics of personality, relationships, learning and memory. Therapists and educators rely on such findings to help guide decisions, and the fact that so many of the studies were called into question could sow doubt in the scientific underpinnings of their work. “I think we knew or suspected that the literature had problems, but to see it so clearly, on such a large scale — it’s unprecedented,” said Jelte Wicherts, an associate professor in the department of methodology and statistics at Tilburg University in the Netherlands. More than 60 of the studies did not hold up. Among them was one on free will. It found that participants who read a passage arguing that their behavior is predetermined were more likely than those who had not read the passage to cheat on a subsequent test. © 2015 The New York Times Company
Link ID: 21355 - Posted: 08.28.2015
By Diana Kwon Each year doctors diagnose approximately 60,000 Americans with Parkinson’s disease, an incurable neurodegenerative condition for which the number-one risk factor is age. Worldwide an estimated seven to 10 million people currently live with the malady. As U.S. and global populations grow older, it is becoming increasingly urgent to understand its causes. So far, researchers know that Parkinson’s involves cell death in a few restricted areas of the brain including the substantia nigra (SNc), one of two big cell clusters in the midbrain that house a large population of dopamine neurons. These cells release dopamine and are involved in a variety of functions including reward processing and voluntary movement. Their death leads to the motor control and balance issues that are core symptoms of the disease. New research shows that these brain cells, most at risk in Parkinson’s disease, require unusually high amounts of energy to carry out their tasks because of their highly branched structures. Like a massive car with an overheating engine, these neurons are susceptible to burnout and early death. This discovery emerged from a comparison of energy use in nigral dopamine neurons and in similar neurons found in the nearby ventral tegmental area (VTA), also in the midbrain. “We were trying to understand why dopamine neurons of the substantia nigra die in Parkinson’s disease patients while there are so many other brain cells that have no problem at all,” says Louis-Eric Trudeau, a neuroscientist at the University of Montreal and senior author of the study published in the August 27 Current Biology. © 2015 Scientific American,
Link ID: 21353 - Posted: 08.28.2015
By Simon Worrall, National Geographic How do we know we exist? What is the self? These are some of the questions science writer Anil Ananthaswamy asks in his thought-provoking new book, The Man Who Wasn’t There: Investigations Into the Strange New Science of the Self. The answers, he says, may lie in medical conditions like Cotard’s syndrome, Alzheimer’s or body integrity identity disorder, which causes some people to try and amputate their own limbs. Speaking from Berkeley, California, he explains why Antarctic explorer Ernest Shackleton fell victim to the doppelgänger effect; how neuroscience is rewriting our ideas about identity; and how a song by George Harrison of the Beatles offers a critique of the Western view of the self. You dedicate the book to “those of us who want to let go but wonder, who is letting go and of what?” Explain that statement. We always hear within popular culture that we have to “let go,” as a way of dealing with certain situations in our lives. And in some sense you have to wonder about that statement because the person or thing doing the letting go is also probably what has to be let go. In the book, I am trying to get behind the whole issue of what the self is that has to do the letting go; and what aspects of the self have to be let go of. You start your book with Alzheimer’s. Tell us about the origin of the condition and what it tells us about “the autobiographical self.” Alzheimer’s is a very severe condition, especially during the mid- to late stages, which starts robbing people of their ability to remember anything that’s happening to them. They also start forgetting the people they are close to. © 1996-2015 National Geographic Society
Link ID: 21343 - Posted: 08.27.2015
While some research suggests that a diet high in omega-3 fatty acids can protect brain health, a large clinical trial by researchers at the National Institutes of Health found that omega-3 supplements did not slow cognitive decline in older persons. With 4,000 patients followed over a five-year period, the study is one of the largest and longest of its kind. It was published today in the Journal of the American Medical Association. “Contrary to popular belief, we didn’t see any benefit of omega-3 supplements for stopping cognitive decline,” said Emily Chew, M.D., . Dr. Chew leads the Age-Related Eye Disease Study (AREDS), which was designed to investigate a combination of nutritional supplements for slowing age-related macular degeneration (AMD), a major cause of vision loss among older Americans. That study established that daily high doses of certain antioxidants and minerals — called the AREDS formulation — can help slow the progression to advanced AMD. A later study, called AREDS2, tested the addition of omega-3 fatty acids to the AREDS formula. But the omega-3’s made no difference. Omega-3 fatty acids are made by marine algae and are concentrated in fish oils; they are believed to be responsible for the health benefits associated with regularly eating fish, such as salmon, tuna, and halibut.*Where studies have surveyed people on their dietary habits and health, they’ve found that regular consumption of fish is associated with lower rates of AMD, cardiovascular disease, and possibly dementia. “We’ve seen data that eating foods with omega-3 may have a benefit for eye, brain, and heart health,” Dr. Chew explained.
Link ID: 21340 - Posted: 08.26.2015
By Michelle Roberts Health editor, BBC News online People genetically prone to low vitamin-D levels are at increased risk of multiple sclerosis, a large study suggests. The findings, based on the DNA profiles of tens of thousands of people of European descent, add weight to the theory that the sunshine vitamin plays a role in MS. Scientists are already testing whether giving people extra vitamin D might prevent or ease MS. Experts say the jury is still out. It is likely that environmental and genetic factors are involved in this disease of the nerves in the brain and spinal cord, they say. And if you think you may not be getting sufficient vitamin D from sunlight or your diet, you should discuss this with your doctor. Taking too much vitamin D can also be dangerous. Research around the world already shows MS is more common in less sunny countries, further from the equator. But it is not clear if this relationship is causal - other factors might be at play. To better understand the association, investigators at McGill University in Canada compared the prevalence of MS in a large group of Europeans with and without a genetic predisposition to low vitamin D. © 2015 BBC.
Keyword: Multiple Sclerosis
Link ID: 21339 - Posted: 08.26.2015
Aaron E. Carroll If there is one health myth that will not die, it is this: You should drink eight glasses of water a day. It’s just not true. There is no science behind it. And yet every summer we are inundated with news media reports warning that dehydration is dangerous and also ubiquitous. These reports work up a fear that otherwise healthy adults and children are walking around dehydrated, even that dehydration has reached epidemic proportions. Let’s put these claims under scrutiny. I was a co-author of a paper back in 2007 in the BMJ on medical myths. The first myth was that people should drink at least eight 8-ounce glasses of water a day. This paper got more media attention (even in The Times) than pretty much any other research I’ve ever done. It made no difference. When, two years later, we published a book on medical myths that once again debunked the idea that we need eight glasses of water a day, I thought it would persuade people to stop worrying. I was wrong again. Many people believe that the source of this myth was a 1945 Food and Nutrition Board recommendation that said people need about 2.5 liters of water a day. But they ignored the sentence that followed closely behind. It read, “Most of this quantity is contained in prepared foods.” Water is present in fruits and vegetables. It’s in juice, it’s in beer, it’s even in tea and coffee. Before anyone writes me to tell me that coffee is going to dehydrate you, research shows that’s not true either. Although I recommended water as the best beverage to consume, it’s certainly not your only source of hydration. You don’t have to consume all the water you need through drinks. You also don’t need to worry so much about never feeling thirsty. The human body is finely tuned to signal you to drink long before you are actually dehydrated. © 2015 The New York Times Company
Link ID: 21335 - Posted: 08.25.2015
By JOAN RAYMOND Rita Gunther McGrath, a Columbia Business School professor, is one of those business travelers who do not care about delays, cancellations or navigating a new location. What does concern her is the seeming inability to conquer jet lag, and the accompanying symptoms that leave her groggy, unfocused and feeling, she says, “like a dishrag.” “Jet lag has always been an issue for me,” says Ms. McGrath, who has been a business traveler for more than two decades and has dealt with itineraries that take her from New York to New Zealand to Helsinki to Hong Kong all within a matter of days. She has scoured the Internet for “jet lag cures,” and has tried preventing or dealing with the misery by avoiding alcohol, limiting light exposure or blasting her body with sunlight and “doing just about anything and everything that experts tell you to do,” Ms. McGrath said. “Jet lag is not conducive to the corporate environment,” she said. “There has to be some kind of help that actually works for those of us that travel a lot, but I sure can’t find it.” Although science is closer to understanding the basic biological mechanisms that make many travelers feel so miserable when crossing time zones, research has revealed that, at least for now, there is no one-size fits-all recommendation for preventing or dealing with the angst of jet lag. Recommendations to beat jet lag include adjusting sleep schedules, short-term use of medications to sleep or stay awake, melatonin supplements and light exposure timing, among others, said Col. Ian Wedmore, an emergency medicine specialist for the Army. © 2015 The New York Times Company
Keyword: Biological Rhythms
Link ID: 21333 - Posted: 08.25.2015
By Hanae Armitage The libido enhancement drug flibanserin (trade name Addyi) took center stage last week after winning long-sought approval from the U.S. Food and Drug Administration (FDA). The coverage from advocates and nonbelievers has run the gamut—advice, caution, and criticism likely to confuse undecided—but curious—onlookers. But exactly how Addyi drums up sex drive is still murky. The drug has a long backstory. It was originally investigated in 1995 by pharmacologist Franco Borsini and a team of researchers at Boehringer Ingelheim Italia in Milan as an antidepressant because of its ability to regulate neurotransmitters—the brain’s chemical-signaling molecules. In particular, the team suspected that the drug regulated three key neurotransmitters thought to influence mood: serotonin, dopamine, and norepinephrine. A clinical trial found it did little to alleviate depression, but did seem to have an effect on mood. It just wasn’t the mood the researchers were expecting. These early trials tipped clinicians to flibanserin’s more prominent role in sexual health, as female subjects had higher scores on the Arizona Sexual Experience Scale, a survey that asks participants to rate their satisfaction on a variety of sexual health topics, like how often participants felt sexual desire and how intense that desire was. A separate group of researchers, also at Boehringer Ingelheim, completed their first clinical trials to explore flibanserin as a libido-enhancer in 2008. They measured levels of desire through a journal-based evaluation in which subjects recorded their levels of sexual drive on a daily basis. But FDA twice concluded that the resulting increases in libido were not statistically significant, and regulators were wary of potentially dangerous side effects like dizziness, sleepiness, nausea, and fainting. © 2015 American Association for the Advancement of Science
Keyword: Sexual Behavior
Link ID: 21332 - Posted: 08.25.2015
By NINA STROHMINGER and SHAUN NICHOLS WHEN does the deterioration of your brain rob you of your identity, and when does it not? Alzheimer’s, the neurodegenerative disease that erodes old memories and the ability to form new ones, has a reputation as a ruthless plunderer of selfhood. People with the disease may no longer seem like themselves. Neurodegenerative diseases that target the motor system, like amyotrophic lateral sclerosis, can lead to equally devastating consequences: difficulty moving, walking, speaking and eventually, swallowing and breathing. Yet they do not seem to threaten the fabric of selfhood in quite the same way. Memory, it seems, is central to identity. And indeed, many philosophers and psychologists have supposed as much. This idea is intuitive enough, for what captures our personal trajectory through life better than the vault of our recollections? But maybe this conventional wisdom is wrong. After all, the array of cognitive faculties affected by neurodegenerative diseases is vast: language, emotion, visual processing, personality, intelligence, moral behavior. Perhaps some of these play a role in securing a person’s identity. The challenge in trying in determine what parts of the mind contribute to personal identity is that each neurodegenerative disease can affect many cognitive systems, with the exact constellation of symptoms manifesting differently from one patient to the next. For instance, some Alzheimer’s patients experience only memory loss, whereas others also experience personality change or impaired visual recognition. The only way to tease apart which changes render someone unrecognizable is to compare all such symptoms, across multiple diseases. And that’s just what we did, in a study published this month in Psychological Science. © 2015 The New York Times Company
Link ID: 21331 - Posted: 08.24.2015
Jon Hamilton More than 50 million adults in the U.S. have a disorder such as insomnia, restless leg syndrome or sleep apnea, according to an Institute of Medicine report. And it's now clear that a lack of sleep "not only increases the risk of errors and accidents, it also has adverse effects on the body and brain," according to Charles Czeisler, chief of the division of sleep and circadian disorders at Brigham and Women's hospital in Boston. Research in the past couple of decades has shown that a lack of sleep increases a person's risk for cardiovascular disease, diabetes, infections, and maybe even Alzheimer's disease. Yet most sleep disorders go untreated. Michael Arnott, of Cambridge, Massachusetts, says he used to have terrible trouble staying awake on long drives. Sleep specialists discovered he has obstructive sleep apnea, though not for the most common reasons — he isn't overweight, and doesn't smoke or take sedatives. "I would get groggy and feel like I've got to keep talking, open the window," Arnott says. His wife, Mary White, says being a passenger on those drives could be scary. "All of a sudden there'd be a change in the speed and I'd look over, and his eyes would be starting to close," she remembers. White thought her husband might have sleep apnea, which interferes with breathing. But Arnott was in denial. He figured he was free of most risk factors for apnea. He wasn't overweight, he didn't smoke or take sedatives, and he has always stayed in great shape. So his wife took the initiative. "I asked him to see a doctor and he wouldn't," she says. In 2012, though, White persuaded him to take part in a sleep research study that paid for his participation, and took place at a sleep lab in Boston –not too far from the couple's home in Cambridge. © 2015 NPR
Link ID: 21330 - Posted: 08.24.2015
Richard A. Friedman THANKS to Caitlyn Jenner, and the military’s changing policies, transgender people are gaining acceptance — and living in a bigger, more understanding spotlight than at any previous time. We’re learning to be more accepting of transgender individuals. And we’re learning more about gender identity, too. The prevailing narrative seems to be that gender is a social construct and that people can move between genders to arrive at their true identity. But if gender were nothing more than a social convention, why was it necessary for Caitlyn Jenner to undergo facial surgeries, take hormones and remove her body hair? The fact that some transgender individuals use hormone treatment and surgery to switch gender speaks to the inescapable biology at the heart of gender identity. This is not to suggest that gender identity is simply binary — male or female — or that gender identity is inflexible for everyone. Nor does it mean that conventional gender roles always feel right; the sheer number of people who experience varying degrees of mismatch between their preferred gender and their body makes this very clear. In fact, recent neuroscience research suggests that gender identity may exist on a spectrum and that gender dysphoria fits well within the range of human biological variation. For example, Georg S. Kranz at the Medical University of Vienna and colleagues elsewhere reported in a 2014 study in The Journal of Neuroscience that individuals who identified as transsexuals — those who wanted sex reassignment — had structural differences in their brains that were between their desired gender and their genetic sex. © 2015 The New York Times Company
Keyword: Sexual Behavior
Link ID: 21329 - Posted: 08.24.2015
By Kazi Stastna The U.S. approval of a pill to treat low libido in women has whipped up a whirlwind of debate and raised questions about whether the so-called female Viagra addresses the real reasons for lack of sexual desire. The U.S. Food and Drug Administration last week approved flibanserin, to be sold under the name Addyi starting in October, for the treatment of hypoactive sexual desire disorder (HSDD) among premenopausal women — some two decades after Viagra was approved for the treatment of male erectile dysfunction. Sprout Pharmaceuticals pitched flibanserin as a drug that would finally give women with sexual dysfunction similar treatment options to men and bused dozens of women to FDA hearings in Maryland to attest to its benefits and plead for its approval in what some saw as a heavy-handed and misleading public relations campaign. The FDA gave flibanserin the OK after twice rejecting it and despite concerns about its risks and modest efficacy because it said women suffering distress from low libido have an "unmet medical need." Days after it did, Canadian pharmaceutical company Valeant offered to buy Sprout for $1 billion US and said it will apply to get flibanserin approved in Canada and other countries. Although often likened to Viagra, flibanserin was created as an antidepressant and works on the brain while erectile dysfunction medications stimulate blood flow to the penis. Critics argue it's an ineffectual pharmacological solution for a problem better treated with relationship counselling, sex therapy and behavioural changes. "Their suffering is real, but the women who testified had a lot of different stories, and some of those stories were very good reasons for having low libido, including having six children, having a one-year-old, having had breast cancer treatment …," says Adriane Fugh-Berman, associate professor of pharmacology and physiology at Georgetown University in Washington, D.C., and director of PharmedOut, a pharmaceutical marketing watchdog group. ©2015 CBC/Radio-Canada.
Keyword: Sexual Behavior
Link ID: 21328 - Posted: 08.24.2015