Chapter 13. Memory, Learning, and Development

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 61 - 80 of 4888

By Fredrick Kunkle Years ago, many scientists assumed that a woman’s heart worked pretty much the same as a man’s. But as more women entered the male-dominated field of cardiology, many such assumptions vanished, opening the way for new approaches to research and treatment. A similar shift is underway in the study of Alzheimer’s disease. It has long been known that more women than men get the deadly neurodegenerative disease, and an emerging body of research is challenging the common wisdom as to why. Although the question is by no means settled, recent findings suggest that biological, genetic and even cultural influences may play heavy roles. Of the more than 5 million people in the United States who have been diagnosed with Alzheimer’s, the leading cause of dementia, two-thirds are women. Because advancing age is considered the biggest risk factor for the disease, researchers largely have attributed that disparity to women’s longer life spans. The average life expectancy for women is 81 years, compared with 76 for men. Yet “even after taking age into account, women are more at risk,” said Richard Lipton, a physician who heads the Einstein Aging Study at Albert Einstein College of Medicine in New York. With the number of Alzheimer’s cases in the United States expected to more than triple by 2050, some researchers are urging a greater focus on understanding the underlying reasons women are more prone to the disease and on developing gender-specific treatments. The area of inquiry has been growing in part because of a push by female Alzheimer’s researchers, who have formed a group to advocate for a larger leadership role in the field and more gender-specific research.

Keyword: Alzheimers; Aggression
Link ID: 20034 - Posted: 09.04.2014

By Kate Wong In 1871 Charles Darwin surmised that humans were evolutionarily closer to the African apes than to any other species alive. The recent sequencing of the gorilla, chimpanzee and bonobo genomes confirms that supposition and provides a clearer view of how we are connected: chimps and bonobos in particular take pride of place as our nearest living relatives, sharing approximately 99 percent of our DNA, with gorillas trailing at 98 percent. Yet that tiny portion of unshared DNA makes a world of difference: it gives us, for instance, our bipedal stance and the ability to plan missions to Mars. Scientists do not yet know how most of the DNA that is uniquely ours affects gene function. But they can conduct whole-genome analyses—with intriguing results. For example, comparing the 33 percent of our genome that codes for proteins with our relatives' genomes reveals that although the sum total of our genetic differences is small, the individual differences pervade the genome, affecting each of our chromosomes in numerous ways. © 2014 Scientific American

Keyword: Evolution; Aggression
Link ID: 20030 - Posted: 09.03.2014

By Virginia Morell Figaro, a Goffin’s cockatoo (Cacatua goffini) housed at a research lab in Austria, stunned scientists a few years ago when he began spontaneously making stick tools from the wooden beams of his aviary. The Indonesian parrots are not known to use tools in the wild, yet Figaro confidently employed his sticks to rake in nuts outside his wire enclosure. Wondering if Figaro’s fellow cockatoos could learn by watching his methods, scientists set up experiments for a dozen of them. One group watched as Figaro used a stick to reach a nut placed inside an acrylic box with a wire-mesh front panel; others saw “ghost demonstrators”—magnets that were hidden beneath a table and that the researchers controlled—displace the treats. Each bird was then placed in front of the box, with a stick just like Figaro’s lying nearby. The group of three males and three females that had watched Figaro also picked up the sticks, and made some efforts reminiscent of his actions. But only those three males, such as the one in the photo above, became proficient with the tool and successfully retrieved the nuts, the scientists report online today in the Proceedings of the Royal Society B. None of the females did so; nor did any of the birds, male or female, in the ghost demonstrator group. Because the latter group failed entirely, the study shows that the birds need living teachers, the scientists say. Intriguingly, the clever observers developed a better technique than Figaro’s for getting the treat. Thus, the cockatoos weren’t copying his exact actions, but emulating them—a distinction that implies some degree of creativity. Two of the successful cockatoos were later given a chance to make a tool of their own. One did so immediately (as in the video above), and the other succeeded after watching Figaro. It may be that by learning to use a tool, the birds are stimulated to make tools of their own, the scientists say. © 2014 American Association for the Advancement of Science.

Keyword: Learning & Memory
Link ID: 20027 - Posted: 09.03.2014

by Chris Higgins Neuroscientists have pinpointed where imagination hides in the brain and found it to be functionally distinct from related processes such as memory. The team from Brigham Young University (BYU), Utah-- including research proposer, undergraduate student Stefania Ashby -- used functional Magnetic Resonance Imaging (fMRI) to observe brain activity when subjects were remembering specific experiences and putting themselves in novel ones. "I was thinking a lot about planning for my own future and imagining myself in the future, and I started wondering how memory and imagination work together," Ashby said. "I wondered if they were separate or if imagination is just taking past memories and combining them in different ways to form something I've never experienced before." The two processes of remembering and imagining have been previously proposed to be the same cognitive task, and so thought to be carried out by the same areas of the brain. However, the experiments derived by Ashby and her mentor (and coauthor) BYU professor Brock Kirwan have refuted these ideas. The studies -- published in the journal Cognitive Neuroscience -- required participants to submit 60 photographs of previous life events and use them to create prompts for the "remember" sections. They then carried out a questionnaire before putting the subject into the MRI scanner to determine what scenarios were the most novel to them and force them into imagination. Then, under fMRI testing, the subjects were prompted with various scenarios and the areas of their brain that became active during each scenario was correlated with each scene's familiarity -- pure memory, or imagination. © Condé Nast UK 2014

Keyword: Learning & Memory; Aggression
Link ID: 20026 - Posted: 09.03.2014

By JOHN ROGERS LOS ANGELES (AP) — The founder of a Los Angeles-based nonprofit that provides free music lessons to low-income students from gang-ridden neighborhoods began to notice several years ago a hopeful sign: Kids were graduating high school and heading off to UCLA, Tulane and other big universities. That’s when Margaret Martin asked how the children in the Harmony Project were beating the odds. Researchers at Northwestern University in Illinois believe that the students’ music training played a role in their educational achievement, helping as Martin noticed 90 percent of them graduate from high school while 50 percent or more didn’t from those same neighborhoods. A two-year study of 44 children in the program shows that the training changes the brain in ways that make it easier for youngsters to process sounds, according to results reported in Tuesday’s edition of The Journal of Neuroscience. That increased ability, the researchers say, is linked directly to improved skills in such subjects as reading and speech. But, there is one catch: People have to actually play an instrument to get smarter. They can’t just crank up the tunes on their iPod. Nina Kraus, the study’s lead researcher and director of Northwestern’s auditory neuroscience laboratory, compared the difference to that of building up one’s body through exercise. ‘‘I like to say to people: You’re not going to get physically fit just watching sports,’’ she said.

Keyword: Hearing; Aggression
Link ID: 20025 - Posted: 09.03.2014

By RONI CARYN RABIN Pregnant women often go to great lengths to give their babies a healthy start in life. They quit smoking, skip the chardonnay, switch to decaf, forgo aspirin. They say no to swordfish and politely decline Brie. Yet they rarely wean themselves from popular selective serotonin reuptake inhibitor antidepressants like Prozac, Celexa and Zoloft despite an increasing number of studies linking prenatal exposure to birth defects, complications after birth and even developmental delays and autism. Up to 14 percent of pregnant women take antidepressants, and the Food and Drug Administration has issued strong warnings that one of them, paroxetine (Paxil), may cause birth defects. But the prevailing attitude among doctors has been that depression during pregnancy is more dangerous to mother and child than any drug could be. Now a growing number of critics are challenging that assumption. “If antidepressants made such a big difference, and women on them were eating better, sleeping better and taking better care of themselves, then one would expect to see better birth outcomes among the women who took medication than among similar women who did not,” said Barbara Mintzes, an associate professor at the University of British Columbia School of Population and Public Health. “What’s striking is that there’s no research evidence showing that.” On the contrary, she said, “when you look for it, all you find are harms.” S.S.R.I.s are believed to work in part by blocking reabsorption (or reuptake) of serotonin, altering levels of this important neurotransmitter in the brain and elsewhere in the body. Taken by a pregnant woman, the drugs cross the placental barrier, affecting the fetus. © 2014 The New York Times Company

Keyword: Depression; Aggression
Link ID: 20020 - Posted: 09.02.2014

Moheb Costandi Autism can be baffling, appearing in various forms and guises and thwarting our best attempts to understand the minds of people affected by it. Anything we know for sure about the disorder can probably be traced back to the pioneering research of the developmental psychologist Uta Frith. Frith was the first to propose that people with autism lack theory of mind, the ability to attribute beliefs, intentions and desires to others. She also recognized the superior perceptual abilities of many with the disorder — and their tendency to be unable to see the forest for the trees. Frith, now affiliated with the Institute of Cognitive Neuroscience at University College London (UCL), has shaped autism research for an entire generation of investigators. Meanwhile, her husband Chris Frith formulated a new view of schizophrenia, a mental illness marked by hallucinations, disordered thinking and apathy. His work explored how the disorder affects the experience of agency, the sense that we are in control of our bodies and responsible for our actions. And his innovations in brain imaging helped researchers examine the relationship between brain and mind. Independently, husband and wife explored the social and cognitive aspects of these psychiatric disorders. Together, they helped lay the foundations of cognitive neuroscience, the discipline that seeks to understand the biological basis of thought processes. Trevor Robbins, a cognitive neuroscientist at the University of Cambridge in the U.K., calls them “tremendously influential pioneers,” in particular because both brought a social perspective to cognitive neuroscience. © Copyright 2014 Simons Foundation

Keyword: Autism
Link ID: 20019 - Posted: 09.02.2014

By JAMIE EDGIN and FABIAN FERNANDEZ LAST week the biologist Richard Dawkins sparked controversy when, in response to a woman’s hypothetical question about whether to carry to term a child with Down syndrome, he wrote on Twitter: “Abort it and try again. It would be immoral to bring it into the world if you have the choice.” In further statements, Mr. Dawkins suggested that his view was rooted in the moral principle of reducing overall suffering whenever possible — in this case, that of individuals born with Down syndrome and their families. But Mr. Dawkins’s argument is flawed. Not because his moral reasoning is wrong, necessarily (that is a question for another day), but because his understanding of the facts is mistaken. Recent research indicates that individuals with Down syndrome can experience more happiness and potential for success than Mr. Dawkins seems to appreciate. There are, of course, many challenges facing families caring for children with Down syndrome, including a high likelihood that their children will face surgery in infancy and Alzheimer’s disease in adulthood. But at the same time, studies have suggested that families of these children show levels of well-being that are often greater than those of families with children with other developmental disabilities, and sometimes equivalent to those of families with nondisabled children. These effects are prevalent enough to have been coined the “Down syndrome advantage.” In 2010, researchers reported that parents of preschoolers with Down syndrome experienced lower levels of stress than parents of preschoolers with autism. In 2007, researchers found that the divorce rate in families with a child with Down syndrome was lower on average than that in families with a child with other congenital abnormalities and in those with a nondisabled child. © 2014 The New York Times Company

Keyword: Genes & Behavior; Aggression
Link ID: 20016 - Posted: 08.30.2014

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 PAM BELLUCK Memories and the feelings associated with them are not set in stone. You may have happy memories about your family’s annual ski vacation, but if you see a tragic accident on the slopes, those feelings may change. You might even be afraid to ski that mountain again. Now, using a technique in which light is used to switch neurons on and off, neuroscientists at the Massachusetts Institute of Technology appear to have unlocked some secrets about how the brain attaches emotions to memories and how those emotions can be adjusted. Their research, published Wednesday in the journal Nature, was conducted on mice, not humans, so the findings cannot immediately be translated to the treatment of patients. But experts said the experiments may eventually lead to more effective therapies for people with psychological problems such as depression, anxiety or post-traumatic stress disorder. “Imagine you can go in and find a particular traumatic memory and turn it off or change it somehow,” said David Moorman, an assistant professor of psychological and brain sciences at the University of Massachusetts Amherst, who was not involved in the research. “That’s still science fiction, but with this we’re getting a lot closer to it.” The M.I.T. scientists labeled neurons in the brains of mice with a light-sensitive protein and used pulses of light to switch the cells on and off, a technique called optogenetics. Then they identified patterns of neurons activated when mice created a negative memory or a positive one. A negative memory formed when mice received a mild electric shock to their feet; a positive one was formed when the mice, all male, were allowed to spend time with female mice. © 2014 The New York Times Company

Keyword: Learning & Memory; Aggression
Link ID: 20010 - Posted: 08.28.2014

by Penny Sarchet Memory is a fickle beast. A bad experience can turn a once-loved coffee shop or holiday destination into a place to be avoided. Now experiments in mice have shown how such associations can be reversed. When forming a memory of a place, the details of the location and the associated emotions are encoded in different regions of the brain. Memories of the place are formed in the hippocampus, whereas positive or negative associations are encoded in the amygdala. In experiments with mice in 2012, a group led by Susumo Tonegawa of the Massachusetts Institute of Technology managed to trigger the fear part of a memory associated with a location when the animals were in a different location. They used a technique known as optogenetics, which involves genetically engineering mice so that their brains produce a light-sensitive protein in response to a certain cue. In this case, the cue was the formation of the location memory. This meant the team could make the mouse recall the location just by flashing pulses of light down an optical fibre embedded in the skull. The mice were given electric shocks while their memories of the place were was being formed, so that the animals learned to associate that location with pain. Once trained, the mice were put in a new place and a pulse of light was flashed into their brains. This activated the neurons associated with the original location memory and the mice froze, terrified of a shock, demonstrating that the emotion associated with the original location could be induced by reactivating the memory of the place. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Aggression
Link ID: 20009 - Posted: 08.28.2014

Learning is easier when it only requires nerve cells to rearrange existing patterns of activity than when the nerve cells have to generate new patterns, a study of monkeys has found. The scientists explored the brain’s capacity to learn through recordings of electrical activity of brain cell networks. The study was partly funded by the National Institutes of Health. “We looked into the brain and may have seen why it’s so hard to think outside the box,” said Aaron Batista, Ph.D., an assistant professor at the University of Pittsburgh and a senior author of the study published in Nature, with Byron Yu, Ph.D., assistant professor at Carnegie Mellon University, Pittsburgh. The human brain contains nearly 86 billion neurons, which communicate through intricate networks of connections. Understanding how they work together during learning can be challenging. Dr. Batista and his colleagues combined two innovative technologies, brain-computer interfaces and machine learning, to study patterns of activity among neurons in monkey brains as the animals learned to use their thoughts to move a computer cursor. “This is a fundamental advance in understanding the neurobiological patterns that underlie the learning process,” said Theresa Cruz, Ph.D., a program official at the National Center for Medical Rehabilitations Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “The findings may eventually lead to new treatments for stroke as well as other neurological disorders.”

Keyword: Learning & Memory; Aggression
Link ID: 20008 - Posted: 08.28.2014

|By Michael Leon I had been working quite happily on the basic biology of the brain when a good friend of mine called for advice about his daughter, who had just been diagnosed with autism. I could hear the anguish and fear in his voice when he asked me whether there was anything that could be done to make her better. I told him about the standard-care therapies, including Intensive Behavioral Intervention, Early Intensive Behavioral Intervention, Applied Behavior Analysis, and the Early Start Denver Model (ESDM). These therapies also are expensive, time-consuming and have variable outcomes, with the best outcomes seen for ESDM. There are, however, few ESDM therapists, and the cost of such intensive therapy can be quite high. Moreover, my friend’s daughter was already past the age of the oldest children in the study that demonstrated the efficacy of ESDM. My feeling was that there was a good chance that there was an effective therapy for her using a simple, inexpensive at-home approach involving daily exposure to a wide variety of sensory stimulation. This is a partial list of the disorders whose symptoms can be greatly reduced, or even completely reversed, with what is known as “environmental enrichment”: Autism Stroke Seizures Brain damage Neuronal death during aging ADHD Prenatal alcohol syndrome Lead exposure Multiple sclerosis Addiction Schizophrenia Memory loss Huntington’s disease Parkinson’s disease Alzheimer’s disease Down syndrome Depression But why haven’t you heard about this? The reason is that all of these disorders that have been successfully treated only in animal models of these neurological problems. However, the effects seen in lab animals can be dramatic. © 2014 Scientific American,

Keyword: Autism; Aggression
Link ID: 20003 - Posted: 08.27.2014

|By Roni Jacobson Children are notoriously unreliable witnesses. Conventional wisdom holds that they frequently “remember” things that never happened. Yet a large body of research indicates that adults actually generate more false memories than children. Now a new study finds that children are just as susceptible to false memories as adults, if not more so. Scientists may simply have been using the wrong test. Traditionally, researchers have explored false memories by presenting test subjects with a list of associated words (for instance, “weep,” “sorrow” and “wet”) thematically related to a word not on the list (in this case, “cry”) and then asking them what words they remember. Adults typically mention the missing related word more often than children do—possibly because their life experiences enable them to draw associations between concepts more readily, says Henry Otgaar, a forensic psychologist at Maastricht University in the Netherlands and co-author of the new paper, published in May in the Journal of Experimental Child Psychology. Instead of using word lists to investigate false memories, Otgaar and his colleagues showed participants pictures of scenes, including a classroom, a funeral and a beach. After a short break, they asked those participants whether they remembered seeing certain objects in each picture. Across three experiments, seven- and eight-year-old children consistently reported seeing more objects that were not in the pictures than adults did. © 2014 Scientific American

Keyword: Learning & Memory; Aggression
Link ID: 19999 - 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.

Keyword: Development of the Brain; Aggression
Link ID: 19998 - Posted: 08.26.2014

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

|By Mark Fischetti Parents, students and teachers often argue, with little evidence, about whether U.S. high schools begin too early in the morning. In the past three years, however, scientific studies have piled up, and they all lead to the same conclusion: a later start time improves learning. And the later the start, the better. Biological research shows that circadian rhythms shift during the teen years, pushing boys and girls to stay up later at night and sleep later into the morning. The phase shift, driven by a change in melatonin in the brain, begins around age 13, gets stronger by ages 15 and 16, and peaks at ages 17, 18 or 19. Does that affect learning? It does, according to Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement at the University of Minnesota. She published a large study in February that tracked more than 9,000 students in eight public high schools in Minnesota, Colorado and Wyoming. After one semester, when school began at 8:35 a.m. or later, grades earned in math, English, science and social studies typically rose a quarter step—for example, up halfway from B to B+. Two journal articles that Wahlstrom has reviewed but have not yet been published reach similar conclusions. So did a controlled experiment completed by the U.S. Air Force Academy, which required different sets of cadets to begin at different times during their freshman year. A 2012 study of North Carolina school districts that varied school times because of transportation problems showed that later start times correlated with higher scores in math and reading. Still other studies indicate that delaying start times raises attendance, lowers depression rates and reduces car crashes among teens, all because they are getting more of the extra sleep they need. © 2014 Scientific American

Keyword: Biological Rhythms; Aggression
Link ID: 19989 - Posted: 08.25.2014

By PAM BELLUCK As a baby’s brain develops, there is an explosion of synapses, the connections that allow neurons to send and receive signals. But during childhood and adolescence, the brain needs to start pruning those synapses, limiting their number so different brain areas can develop specific functions and are not overloaded with stimuli. Now a new study suggests that in children with autism, something in the process goes awry, leaving an oversupply of synapses in at least some parts of the brain. The finding provides clues to how autism develops from childhood on, and may help explain some symptoms like oversensitivity to noise or social experiences, as well as why many people with autism also have epileptic seizures. It could also help scientists in the search for treatments, if they can develop safe therapies to fix the system the brain uses to clear extra synapses. The study, published Thursday in the journal Neuron, involved tissue from the brains of children and adolescents who had died from ages 2 to 20. About half had autism; the others did not. The researchers, from Columbia University Medical Center, looked closely at an area of the brain’s temporal lobe involved in social behavior and communication. Analyzing tissue from 20 of the brains, they counted spines — the tiny neuron protrusions that receive signals via synapses — and found more spines in children with autism. The scientists found that at younger ages, the number of spines did not differ tremendously between the two groups of children, but adolescents with autism had significantly more than those without autism. Typical 19-year-olds had 41 percent fewer synapses than toddlers, but those in their late teenage years with autism had only 16 percent fewer than young children with autism. © 2014 The New York Times Company

Keyword: Autism; Aggression
Link ID: 19988 - Posted: 08.22.2014

|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,

Keyword: Learning & Memory; Aggression
Link ID: 19985 - Posted: 08.22.2014