Chapter 16. None
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Carl Zimmer An unassuming single-celled organism called Toxoplasma gondii is one of the most successful parasites on Earth, infecting an estimated 11 percent of Americans and perhaps half of all people worldwide. It’s just as prevalent in many other species of mammals and birds. In a recent study in Ohio, scientists found the parasite in three-quarters of the white-tailed deer they studied. One reason for Toxoplasma’s success is its ability to manipulate its hosts. The parasite can influence their behavior, so much so that hosts can put themselves at risk of death. Scientists first discovered this strange mind control in the 1990s, but it’s been hard to figure out how they manage it. Now a new study suggests that Toxoplasma can turn its host’s genes on and off — and it’s possible other parasites use this strategy, too. Toxoplasma manipulates its hosts to complete its life cycle. Although it can infect any mammal or bird, it can reproduce only inside of a cat. The parasites produce cysts that get passed out of the cat with its feces; once in the soil, the cysts infect new hosts. Toxoplasma returns to cats via their prey. But a host like a rat has evolved to avoid cats as much as possible, taking evasive action from the very moment it smells feline odor. Experiments on rats and mice have shown that Toxoplasma alters their response to cat smells. Many infected rodents lose their natural fear of the scent. Some even seem to be attracted to it. Manipulating the behavior of a host is a fairly common strategy among parasites, but it’s hard to fathom how they manage it. A rat’s response to cat odor, for example, emerges from complex networks of neurons that detect an odor, figure out its source and decide on the right response in a given moment. © 2014 The New York Times Company
Memory can be boosted by using a magnetic field to stimulate part of the brain, a study has shown. The effect lasts at least 24 hours after the stimulation is given, improving the ability of volunteers to remember words linked to photos of faces. Scientists believe the discovery could lead to new treatments for loss of memory function caused by ageing, strokes, head injuries and early Alzheimer's disease. Dr Joel Voss, from Northwestern University in Chicago, said: "We show for the first time that you can specifically change memory functions of the brain in adults without surgery or drugs, which have not proven effective. "This non-invasive stimulation improves the ability to learn new things. It has tremendous potential for treating memory disorders." The scientists focused on associative memory, the ability to learn and remember relationships between unrelated items. An example of associative memory would be linking someone to a particular restaurant where you both once dined. It involves a network of different brain regions working in concert with a key memory structure called the hippocampus, which has been compared to an "orchestra conductor" directing brain activity. Stimulating the hippocampus caused the "musicians" – the brain regions – to "play" more in time, thereby tightening up their performance. A total of 16 volunteers aged 21-40 took part in the study, agreeing to undergo 20 minutes of transcranial magnetic stimulation (TMS) every day for five days. © 2014 Guardian News and Media Limited
Keyword: Learning & Memory
Link ID: 20015 - Posted: 08.30.2014
by Michael Slezak It's odourless, colourless, tasteless and mostly non-reactive – but it may help you forget. Xenon gas has been shown to erase fearful memories in mice, raising the possibility that it could be used to treat post-traumatic stress disorder (PTSD) if the results are replicated in a human trial next year. The method exploits a neurological process known as "reconsolidation". When memories are recalled, they seem to get re-encoded, almost like a new memory. When this process is taking place, the memories become malleable and can be subtly altered. This new research suggests that at least in mice, the reconsolidation process might be partially blocked by xenon, essentially erasing fearful memories. Among other things, xenon is used as an anaesthetic. Frozen in fear Edward Meloni and his colleagues at Harvard Medical School in Boston trained mice to be afraid of a sound by placing them in a cage and giving them an electric shock after the sound was played. Thereafter, if the mice heard the noise, they would become frightened and freeze. Later, the team played the sound and then gave the mice either a low dose of xenon gas for an hour or just exposed them to normal air. Mice that were exposed to xenon froze for less time in response to the sound than the other mice. © Copyright Reed Business Information Ltd.
Keyword: Learning & Memory
Link ID: 20014 - Posted: 08.30.2014
By GARY GREENBERG Joel Gold first observed the Truman Show delusion — in which people believe they are the involuntary subjects of a reality television show whose producers are scripting the vicissitudes of their lives — on Halloween night 2003 at Bellevue Hospital, where he was the chief attending psychiatrist. “Suspicious Minds,” which he wrote with his brother, Ian, an associate professor of philosophy and psychology at McGill University, is an attempt to use this delusion, which has been observed by many clinicians, to pose questions that have gone out of fashion in psychiatry over the last half-century: Why does a mentally ill person have the delusions he or she has? And, following the lead of the medical historian Roy Porter, who once wrote that “every age gets the lunatics it deserves,” what can we learn about ourselves and our times from examining the content of madness? The Golds’ answer is a dual broadside: against a psychiatric profession that has become infatuated with neuroscience as part of its longstanding attempt to establish itself as “real medicine,” and against a culture that has become too networked for its own good. Current psychiatric practice is to treat delusions as the random noise generated by a malfunctioning (and mindless) brain — a strategy that would be more convincing if doctors had a better idea of how the brain produced madness and how to cure it. According to the Golds, ignoring the content of delusions like T.S.D. can only make mentally ill people feel more misunderstood, even as it distracts the rest of us from the true significance of the delusion: that we live in a society that has put us all under surveillance. T.S.D. sufferers may be paranoid, but that does not mean they are wrong to think the whole world is watching. This is not to say they aren’t crazy. Mental illness may be “just a frayed, weakened version of mental health,” but what is in tatters for T.S.D. patients is something crucial to negotiating social life, and that, according to the Golds, is the primary purpose toward which our big brains have evolved: the ability to read other people’s intentions or, as cognitive scientists put it, to have a theory of mind. This capacity is double-edged. “The better you are at ToM,” they write, “the greater your capacity for friendship.” © 2014 The New York Times Company
Link ID: 20013 - Posted: 08.30.2014
By Virginia Morell A dog’s bark may sound like nothing but noise, but it encodes important information. In 2005, scientists showed that people can tell whether a dog is lonely, happy, or aggressive just by listening to his bark. Now, the same group has shown that dogs themselves distinguish between the barks of pooches they’re familiar with and the barks of strangers and respond differently to each. The team tested pet dogs’ reactions to barks by playing back recorded barks of a familiar and unfamiliar dog. The recordings were made in two different settings: when the pooch was alone, and when he was barking at a stranger at his home’s fence. When the test dogs heard a strange dog barking, they stayed closer to and for a longer period of time at their home’s gate than when they heard the bark of a familiar dog. But when they heard an unknown and lonely dog barking, they stayed close to their house and away from the gate, the team reports this month in Applied Animal Behaviour Science. They also moved closer toward their house when they heard a familiar dog’s barks, and they barked more often in response to a strange dog barking. Dogs, the scientists conclude from this first study of pet dogs barking in their natural environment (their owners’ homes), do indeed pay attention to and glean detailed information from their fellows’ barks. © 2014 American Association for the Advancement of Science
By ANNA NORTH “You can learn a lot from what you see on a screen,” said Yalda T. Uhls. However, she told Op-Talk, “It’s not going to give you context. It’s not going to give you the big picture.” Ms. Uhls, a researcher at the Children’s Digital Media Center in Los Angeles, was part of a team that looked at what happened when kids were separated from their screens — phones, iPads, laptops and the like — for several days. Their findings may have implications for adults’ relationship to technology, too. For a paper published in the journal Computers in Human Behavior, the researchers studied 51 sixth-graders who attended a five-day camp where no electronic devices were allowed. Before and after the camp, they tested the kids’ emotion-recognition skills using photos of facial expressions and sound-free video clips designed to measure their reading of nonverbal cues. The kids did significantly better on both tests after five screen-free days; a group of sixth-graders from the same school who didn’t go to camp showed less or no improvement. Ms. Uhls, who also works for the nonprofit Common Sense Media, told Op-Talk that a number of factors might have been at play in the campers’ improvement. For instance, their time in nature might have played a role. But to her, the most likely explanation was the sheer increase in face-to-face interaction: “The issue really is not that staring at screens is going to make you bad at recognizing emotions,” she said. “It’s more that if you’re looking at screens you’re not looking at the world, and you’re not looking at people.” Many adults have sought out the same Internet-free experience the kids had, though they usually don’t go to camp to get it. The novelist Neil Gaiman took a “sabbatical from social media” in 2013, “so I can concentrate on my day job: making things up.” © 2014 The New York Times Company
Link ID: 20006 - Posted: 08.28.2014
By Michael Balter Humans are generally highly cooperative and often impressively altruistic, quicker than any other animal species to help out strangers in need. A new study suggests that our lineage got that way by adopting so-called cooperative breeding: the caring for infants not just by the mother, but also by other members of the family and sometimes even unrelated adults. In addition to helping us get along with others, the advance led to the development of language and complex civilizations, the authors say. Cooperative breeding is not unique to humans. Up to 10% of birds are cooperative breeders, as are meerkats and New World monkeys such as tamarins and marmosets. But our closest primate relatives, great apes such as chimpanzees, are not cooperative breeders. Because the human and chimpanzee lineages split between 5 million and 7 million years ago, and humans are the only apes that engage in cooperative breeding, researchers have puzzled over how this helping behavior might have evolved all over again on the human line. In the late 1990s, Sarah Blaffer Hrdy, now an anthropologist emeritus at the University of California, Davis, proposed the cooperative breeding hypothesis. According to her model, early in their evolution humans added cooperative breeding behaviors to their already existing advanced ape cognition, leading to a powerful combination of smarts and sociality that fueled even bigger brains, the evolution of language, and unprecedented levels of cooperation. Soon after Hrdy’s proposal, anthropologists Carel van Schaik and Judith Burkart of the University of Zurich in Switzerland began to test some of these ideas, demonstrating that cooperatively breeding primates like marmosets engaged in seemingly altruistic behavior by helping other marmosets get food with no immediate reward to themselves. © 2014 American Association for the Advancement of Science.
Daniel Cressey In many respects, the modern electronic cigarette is not so different from its leaf-and-paper predecessor. Take a drag from the mouthpiece and you get a genuine nicotine fix — albeit from a fluid wicked into the chamber of a battery-powered atomizer and vaporized by a heating element. Users exhale a half-convincing cloud of ‘smoke’, and many e-cigarettes even sport an LED at the tip that glows blue, green or classic red to better simulate the experience romanticized by countless writers and film-makers. The only things missing are the dozens of cancer-causing chemicals found in this digital wonder’s analogue forebears. E-cigarettes — also known as personal vaporizers or electronic nicotine-delivery systems among other names — are perhaps the most disruptive devices that public-health researchers working on tobacco control have ever faced. To some, they promise to snuff out a behaviour responsible for around 100 million deaths in the twentieth century. Others fear that they could perpetuate the habit, and undo decades of work. Now, a group once united against a common enemy is divided. “These devices have really polarized the tobacco-control community,” says Michael Siegel, a physician and tobacco researcher at Boston University School of Public Health in Massachusetts. “You now have two completely opposite extremes with almost no common ground between them.” Evidence is in short supply on both sides. Even when studies do appear, they are often furiously debated. And it is not just researchers who are attempting to catch up with the products now pouring out of Chinese factories: conventional tobacco companies are pushing into the nascent industry, and regulators are scrambling to work out what to do. © 2014 Nature Publishing Group
Keyword: Drug Abuse
Link ID: 20000 - Posted: 08.27.2014
By Priyanka Pulla Humans are late bloomers when compared with other primates—they spend almost twice as long in childhood and adolescence as chimps, gibbons, or macaques do. But why? One widely accepted but hard-to-test theory is that children’s brains consume so much energy that they divert glucose from the rest of the body, slowing growth. Now, a clever study of glucose uptake and body growth in children confirms this “expensive tissue” hypothesis. Previous studies have shown that our brains guzzle between 44% and 87% of the total energy consumed by our resting bodies during infancy and childhood. Could that be why we take so long to grow up? One way to find out is with more precise studies of brain metabolism throughout childhood, but those studies don’t exist yet. However, a new study published online today in the Proceedings of the National Academy of Sciences (PNAS) spliced together three older data sets to provide a test of this hypothesis. First, the researchers used a 1987 study of PET scans of 36 people between infancy and 30 years of age to estimate age trends in glucose uptake by three major sections of the brain. Then, to calculate how uptake varied for the entire brain, they combined that data with the brain volumes and ages of 400 individuals between 4.5 years of age and adulthood, gathered from a National Institutes of Health study and others. Finally, to link age and brain glucose uptake to body size, they used an age series of brain and body weights of 1000 individuals from birth to adulthood, gathered in 1978. © 2014 American Association for the Advancement of Science.
By DAVID LEVINE MONTREAL — When twins have similar personalities, is it mainly because they share so much genetic material or because their physical resemblance makes other people treat them alike? Most researchers believe the former, but the proposition has been hard to prove. So Nancy L. Segal, a psychologist who directs the Twin Studies Center at California State University, Fullerton, decided to test it — and enlisted an unlikely ally. He is François Brunelle, a photographer in Montreal who takes pictures of pairs of people who look alike but are not twins. Dr. Segal was sent to Mr. Brunelle’s website by a graduate student who knew of her research with twins. When she saw the photographs, she realized that the unrelated look-alikes would be ideal study subjects: She could compare their similarities and differences to those of actual twins. “I reasoned that if personality resides in the face,” she said, “then unrelated look-alikes should be as similar in behavior as identical twins reared apart. Alternatively, if personality traits are influenced by genetic factors, then unrelated look-alikes should show negligible personality similarity.” For 14 years, Mr. Brunelle, 64, has been working on a project he calls “I’m Not a Look-Alike!”: more than 200 black-and-white portraits of pairs who do, in fact, look startlingly alike. “I originally named the project ‘Look-Alikes,’ but I felt it was boring and some of the subjects did not feel they looked alike,” he said. “The new name gives ownership to the people I photographed and allows viewers of my website to decide for themselves if the people look alike or not.” Most come to him through social media links to his website. “It has taken on a life of its own,” he said. “I have heard from people in China — and even a man who has an uncle in Uzbekistan who is a dead ringer for former President George W. Bush.” © 2014 The New York Times Company
Keyword: Genes & Behavior
Link ID: 19997 - Posted: 08.26.2014
Erin Allday When a person suddenly loses the ability to speak or to understand what others are saying, the hardships that cascade from that loss can be overwhelming - from the seemingly trite to the devastatingly depressing. What hit Derrick Wong, 49, hardest was losing the ability to tell a joke. Ralph Soriano, 56, hates taking his car to the mechanic, knowing he will barely understand what's being said. "Girls," said Luke Waterman, 30, with a sigh. Flirting used to come easy. All three men - actually a pretty happy, hopeful gang for the most part - are longtime members of a group therapy program at the Aphasia Center of California, an Oakland nonprofit that offers treatment and ongoing education to people who have suffered communication disorders as a result of stroke or other brain injury. The nonprofit specializes in long-term therapy, an area of aphasia treatment that has taken off in the past few years. For many decades, doctors and speech pathologists assumed that patients had a window of six months to a year to recover language skills lost to a brain injury. Now, anecdotal reports and clinical research suggest that the window is much wider, and may even stay open a lifetime. "There is evidence that people can improve and regain skills, even years after a stroke," said Blair Menn, a speech language pathologist at Kaiser Permanente Medical Center in Redwood City. © 2014 Hearst Communications, Inc.
by Jennifer Viegas Spritzing dogs with a “pig perfume” helps prevent them from barking incessantly, jumping frantically on house guests and from engaging in other unwanted behaviors, according to new research. The eau de oink, aka “Boar Mate” or “Stop That,” was formulated by Texas Tech scientist John McGlone, who was looking for a way to curb his Cairn terrier Toto’s non-stop barking. One spritz of the pig perfume seemed to do the trick in an instant without harming his dog. “It was completely serendipitous,” McGlone, who works in the university’s Animal and Food Sciences department of the College of Agriculture and Natural Sciences, said in a press release. “One of the most difficult problems is that dogs bark a lot, and it’s one of the top reasons they are given back to shelters or pounds.” The key ingredient is androstenone, a steroid and pheromone produced by male pigs and released in their saliva and fat. When detected by female pigs in heat, they seem to find the male more attractive. (The females assume a mating stance.) One can imagine that dogs spritzed with the scent should not hang around amorous female pigs, but other than that, the product seems to work, according to McGlone. Androstenone smells pungent and is not very appealing to humans, but it can have an effect on mammal behavior, he said. © 2014 Discovery Communications, LLC.
Keyword: Chemical Senses (Smell & Taste)
Link ID: 19994 - Posted: 08.26.2014
By Chelsea Rice Opioid-related overdose deaths are a bleak public health issue in this country. The percentage of patients who receive opioid prescriptions to treat noncancer pain has almost doubled in the past decade, but the number of overdose-related deaths for women have increased five times as much, according to the Centers for Disease Control and Prevention. To put the nationwide stats in perspective, more women have died each year from drug overdoses than from motor vehicle-related injuries since 2007. For men in the past decade, the rate of opioid overdose deaths has increased three-fold. According to the CDC, women in particular are more likely to be prescribed opioid pain relievers than men, more likely to use them chronically, and more likely to be prescribed them in higher doses. But what if medical marijuana, another option for treating chronic pain, could have an impact on these staggering statistics? Research published today in JAMA Internal Medicine found that states with medical marijuana laws before 2010 had 24.8 percent lower annual opioid overdose deaths on average when compared to states where medical marijuana was illegal. Medical cannabis laws were associated in the study with lower overdose mortality rates that generally strengthened over time. In 2010, for instance, researchers noticed there were 1,729 fewer deaths in states where medical marijuana was legal. The research team, lead by Dr. Marcus A. Bachhuber at the Philadelphia Veterans Affairs Medical Center, examined state medical marijuana laws and opioid overdose deaths using death certificate data from 1999 to 2010.
Keyword: Drug Abuse
Link ID: 19993 - Posted: 08.26.2014
By Sandra G. Boodman When the Philadelphia specialist gently tweaked a spot deep inside Heidi Gribble Camp’s back, she screamed, an expression of both anguish and elation.Camp’s vindication was fueled in large part by her persistence. In 2006, her complaints of severe abdominal pain early in her first pregnancy were brushed aside by her doctor — until she nearly bled to death from a ruptured ectopic pregnancy. That near-fatal hemorrhage was swiftly followed by her sudden lapse into unconsciousness and the discovery of large blood clots in her lung and abdomen, requiring additional emergency surgery. “I told him, ‘You found the pain, this is the best day of my life!’ ” Camp, 32, recalled saying during the June 18 procedure at the Hospital of the University of Pennsylvania. The fact that the interventional radiologist, an expert in minimally invasive surgical procedures, was able to pinpoint and replicate the stabbing pain she had suffered for more than eight years was sweet validation. It proved that Camp wasn’t exaggerating her pain and that it had an identifiable, physical cause, something a series of doctors had come to doubt. Months of recovery followed — as did the first episode of searing back pain. But doctors in Florida, Toronto and Northern Virginia, where Camp lived at various times with her husband, a recently retired professional baseball player — told her they could not find a reason for her agony. Some implied that she was dramatizing normal aches; others rebuffed her inquires about a potential cause that would later prove to be prescient.
Keyword: Pain & Touch
Link ID: 19992 - Posted: 08.26.2014
by Penny Sarchet It's a selfie that might save your sight. An implanted sensor could help people with glaucoma monitor the pressure in their eyes using a smartphone camera. The second biggest cause of blindness after cataracts, glaucoma occurs when fluid builds up in the eye. This raises the pressure, damaging the optic nerve. Accurate pressure readings are crucial for giving the right treatment, but one-off measurements during check-ups produce variable results and can be misleading. Yossi Mandel at Bar-Ilan University in Ramat Gan, Israel, and his colleagues have developed a pressure sensor which can be inserted into the eye during surgery to provide easy, regular monitoring from home. A few millimetres in length, the sensor can be embedded into the synthetic lenses used to replace the natural lenses of people with cataracts. It works like a miniature barometer, and contains a fluid column that rises with eye pressure. The level can be read at any time using a smartphone camera fitted with a special optical adapter. Software then analyses the image and calculates the reading. "Continuous monitoring is a clear unmet need in glaucoma," says Francesca Cordeiro, a glaucoma researcher at University College London. Mandel believes self-monitoring will lead to better treatment of glaucoma, and could enable people to skip unnecessary appointments when their eye pressures are on target. © Copyright Reed Business Information Ltd.
By DAVE PHILIPPS WRAY, Colo. — Behind a tall curtain of corn that hides their real cash crop from prying eyes, the Stanley family is undertaking an audacious effort to expand their medical marijuana business to a national market. For years, the five Stanley brothers, who sell a nonintoxicating strain of cannabis that has gained national attention as a treatment for epilepsy, have grown medical marijuana in greenhouses, under tight state and federal regulations. But this year, they are not only growing marijuana outdoors by the acre, they also plan to ship an oil extracted from their plants to other states. The plan would seem to defy a federal prohibition on the sale of marijuana products across state lines. But the Stanleys have justified it with a simple semantic swap: They now call their crop industrial hemp, based on its low levels of THC, the psychoactive ingredient in pot. “The jump to industrial hemp means we can serve thousands of people instead of hundreds,” said Jared Stanley, 27, who wore muddy Carhartts and a rainbow friendship bracelet as he knelt down to prune his plants. Colorado, which has legalized the sale of marijuana for recreational and medical use, has accepted the new designation. But the real question is whether the federal government will go along. If it does, the impact would be significant, opening the door to interstate sales not just by the Stanleys, but possibly by scores of other medical cannabis growers across the country. But if it does not, the Stanley brothers could be shut down by federal agents. So far, the Drug Enforcement Administration is offering few clues, insisting in public statements that while it is willing to allow marijuana sales in states that have legalized the drug, it might step in if growers try to sell beyond state borders. © 2014 The New York Times Company
Keyword: Drug Abuse
Link ID: 19990 - Posted: 08.25.2014
By Meeri Kim From ultrasonic bat chirps to eerie whale songs, the animal kingdom is a noisy place. While some sounds might have meaning — typically something like “I'm a male, aren't I great?” — no other creatures have a true language except for us. Or do they? A new study on animal calls has found that the patterns of barks, whistles, and clicks from seven different species appear to be more complex than previously thought. The researchers used mathematical tests to see how well the sequences of sounds fit to models ranging in complexity. In fact, five species including the killer whale and free-tailed bat had communication behaviors that were definitively more language-like than random. The study was published online Wednesday in the Proceedings of the Royal Society B. “We're still a very, very long way from understanding this transition from animal communication to human language, and it's a huge mystery at the moment,” said study author and zoologist Arik Kershenbaum, who did the work at the National Institute for Mathematical and Biological Synthesis. “These types of mathematical analyses can give us some clues.” While the most complicated mathematical models come closer to our own speech patterns, the simple models — called Markov processes — are more random and have been historically thought to fit animal calls. “A Markov process is where you have a sequence of numbers or letters or notes, and the probability of any particular note depends only on the few notes that have come before,” said Kershenbaum. So the next note could depend on the last two or 10 notes before it, but there is a defined window of history that can be used to predict what happens next. “What makes human language special is that there's no finite limit as to what comes next,” he said.
By Jane C. Hu Last week, people around the world mourned the death of beloved actor and comedian Robin Williams. According to the Gorilla Foundation in Woodside, California, we were not the only primates mourning. A press release from the foundation announced that Koko the gorilla—the main subject of its research on ape language ability, capable in sign language and a celebrity in her own right—“was quiet and looked very thoughtful” when she heard about Williams’ death, and later became “somber” as the news sank in. Williams, described in the press release as one of Koko’s “closest friends,” spent an afternoon with the gorilla in 2001. The foundation released a video showing the two laughing and tickling one another. At one point, Koko lifts up Williams’ shirt to touch his bare chest. In another scene, Koko steals Williams’ glasses and wears them around her trailer. These clips resonated with people. In the days after Williams’ death, the video amassed more than 3 million views. Many viewers were charmed and touched to learn that a gorilla forged a bond with a celebrity in just an afternoon and, 13 years later, not only remembered him and understood the finality of his death, but grieved. The foundation hailed the relationship as a triumph over “interspecies boundaries,” and the story was covered in outlets from BuzzFeed to the New York Post to Slate. The story is a prime example of selective interpretation, a critique that has plagued ape language research since its first experiments. Was Koko really mourning Robin Williams? How much are we projecting ourselves onto her and what are we reading into her behaviors? Animals perceive the emotions of the humans around them, and the anecdotes in the release could easily be evidence that Koko was responding to the sadness she sensed in her human caregivers. © 2014 The Slate Group LLC.
|By Jason G. Goldman When you do not know the answer to a question, say, a crossword puzzle hint, you realize your shortcomings and devise a strategy for finding the missing information. The ability to identify the state of your knowledge—thinking about thinking—is known as metacognition. It is hard to tell whether other animals are also capable of metacognition because we cannot ask them; studies of primates and birds have not yet been able to rule out simpler explanations for this complex process. Scientists know, however, that some animals, such as western scrub jays, can plan for the future. Western scrub jays, corvids native to western North America, are a favorite of cognitive scientists because they are not “stuck in time”—that is, they are able to remember past events and are known to cache their food in anticipation of hunger, according to psychologist Arii Watanabe of the University of Cambridge. But the question remained: Are they aware that they are planning? Watanabe devised a way to test them. He let five birds watch two researchers hide food, in this case a wax worm. The first researcher could hide the food in any of four cups lined up in front of him. The second had three covered cups, so he could place the food only in the open one. The trick was that the researchers hid their food at the same time, forcing the birds to choose which one to watch. If the jays were capable of metacognition, Watanabe surmised, the birds should realize that they could easily find the second researcher's food. The wax worm had to be in the singular open cup. They should instead prefer keeping their eyes on the setup with four open cups because witnessing where that food went would prove more useful in the future. And that is exactly what happened: the jays spent more time watching the first researcher. The results appeared in the July issue of the journal © 2014 Scientific American,
by Sarah Zielinski PRINCETON, N.J. — Learning can be a quick shortcut for figuring out how to do something on your own. The ability to learn from watching another individual — called social learning — is something that hasn’t been documented in many species outside of primates and birds. But now a lizard can be added to the list of critters that can learn from one another. Young eastern water skinks were able to learn by watching older lizards, Martin Whiting of Macquarie University in Sydney reported August 10 at the Animal Behavior Society meeting at Princeton University. The eastern water skink, which reaches a length of about 30 centimeters, can be found near streams and waterways in eastern Australia. The lizards live up to eight years, and while they don’t live in groups, they often see each other in the wild. That could provide an opportunity for learning from each other. Whiting and his colleagues worked with 18 mature (older than 5 years) and 18 young (1.5 to 2 years) male skinks in the lab. The lizards were placed in bins with a barrier in the middle that was either opaque or transparent. In the first of two experiments, the skinks were given a yellow-lidded container with a mealworm inside. They had to learn to open the lid to get the food. In that task, skinks that could see a demonstrator through a transparent barrier were no better at opening the lid than those who had to figure it out on their own. After watching a demonstrator lizard (top row), the skink in the other half of the tub was supposed to have learned that a mealworm was beneath the blue lid. The skink in the middle arena, however, failed the task when he opened the white lid first.D.W.A. Noble et al/Biology Letters 2014 © Society for Science & the Public 2000 - 2013.