By HARRIET BROWN Christine Stanley will never forget the call. Two weeks after her daughter Emily started kindergarten, the teacher phoned in a panic. Emily would not color, sing or participate in any classroom activities; in fact, she would not say a word to anyone. It was not the first time Christine had received such a call. Emily had not talked at preschool, either. She did not make eye contact with store clerks or talk to nurses at the pediatrician's office. She ran off the playground if another child approached. Mrs. Stanley asked her sister, a special education teacher, what she thought. Mrs. Stanley had to explain the problem because at home and with family Emily's behavior was perfectly normal. Her sister mentioned something called selective mutism, but quickly said that couldn't apply to Emily. "She told me, 'Those children are emotionally disturbed and have been abused,' " Mrs. Stanley recalled. But once she started reading about the condition, she said, "I knew it really was selective mutism." Experts say that Emily's story is typical of children with selective mutism. At home, they behave like typical children, but in social situations, especially at school, they are silent and withdrawn. They might talk to grandparents but not to other relatives; they might whisper to one other child, or talk to no one. Some do not point, nod or communicate in any other way. Copyright 2005 The New York Times Company

Keyword: Language; Development of the Brain
Link ID: 7177 - Posted: 04.12.2005

Work will aid neural-network modeling, studies of learning and disease A simple, elegant method could enable scientists to predict how groups of neurons respond to one another and synchronize their activity, report a group of investigators at Carnegie Mellon University. Their work, in press with "Physical Review Letters," ultimately could help scientists understand how neurons network with one another in learning and disease. The research was conducted at the Center for the Neural Basis of Cognition (CNBC), a joint initiative between Carnegie Mellon and the University of Pittsburgh. "Synchronization is important for information coding and storage in the brain," said Nathan Urban, an assistant professor of biological sciences at the Mellon College of Science and a member of the CNBC. The implications of this work for understanding human development and disease are far-reaching according to Urban, because some types of synchronized nerve activity lead to learning, while others can trigger disabling disorders like epilepsy. Specifically, the study investigators developed a method to calculate the phase-resetting curve (PRC) of living neurons. Like a translation key, a PRC dictates how a given neuron will change its routine firing pattern in response to input from other neurons. "You can think of neurons firing like people clapping after a performance. People don't start out clapping in unison, but then someone sets a beat and everyone follows it. Populations of neurons with similar PRCs can work in the same manner, whereby steady outside input effectively drives them to synchronize their firing," Urban said.

Keyword: Biological Rhythms
Link ID: 7176 - Posted: 04.12.2005

By Gregory M. Lamb | Staff writer of The Christian Science Monitor Most people think of placebos as harmless "sugar pills" given in clinic trials to some participants so that medical researchers can gauge the effects of the real drug on others. But in some trials, the "placebo effect" proves to be as strong as that of the drug. Consistently 30 percent or more of the subjects given placebos will show some improvement by taking the dummy pills. So over the decades a small band of researchers has taken a hard look at those pills. Are they really effective? Should they play a role in medical therapy? A landmark study in 2001 concluded that they weren't useful. It "found little evidence in general that placebos had powerful clinical effects," the New England Journal of Medicine (NEJM) reported. But that hardly put the matter to rest as new studies emerged. A March article in The New Scientist summed up the problem: It listed the placebo effect as one of "13 things that do not make sense" to science. Today the definition of placebo effect has broadened beyond dosing with inert pills to include questions about whether healing is still in part an "art" and issues such as how the relationship between doctors and patients affects treatment outcomes. In its last fiscal year, the National Institutes of Health approved 14 clinical studies that aim to better measure and understand the placebo effect. Some of the most exciting work for scientists has come when they have scanned the brain and measured actual biochemical effects of placebos at work. Copyright © 2005 The Christian Science Monitor.

Keyword: Pain & Touch
Link ID: 7175 - Posted: 06.24.2010

Abstract: This paper presents an evolutionary argument for the role of dreams in the development of human cognitive processes. While a theory by Revonsuo (2000) proposes that dreams allow for threat rehearsal and therefore provide an evolutionary advantage, the goal of this paper is to extend this argument by commenting on other fitness-enhancing aspects of dreams. Rather than a simple threat rehearsal mechanism, it is argued that dreams reflect a more general virtual rehearsal mechanism that is likely to play an important role in the development of human cognitive capacities. This paper draws on current work in cognitive neuroscience and philosophy of mind in developing the argument. Although Freud (1900) proposed that dreaming and, specifically, the meaningful content of dreams are related to mental functioning, the tenuous and misunderstood nature of dreams has made the proposition of empirically providing support for, or falsifying, this claim very problematic. The inability to study the effects of dreams on mental functioning has forced many researchers to view dreams as the result of random neural activity (e.g., the activation-synthesis hypothesis; Hobson and McCarley, 1977). If postulations regarding the random nature of dreams are indeed true, then it becomes challenging to construct a theory of how the phenomenology of the dream state could serve a functional role and be better understood through an evolutionary analysis. However, recent research, to be discussed in this paper, which takes into account the physiological mechanisms underlying sleep and dreams, the content of dreams, and the environmental conditions of selection, points toward the natural selection of dreaming as a state of consciousness which has persisted across the development of the human species. This tends to suggest that the dream state was selected for as an adaptation which increases overall fitness.

Keyword: Sleep
Link ID: 7174 - Posted: 04.12.2005

Learning and memory are processes that link experience with behavior and therefore play central roles in our daily experience. That there exists a physical basis for these processes seems at first hard to imagine--except for the fact that physical disruptions in the brain, such as stroke or disease, can make them go wrong. This week, researchers report that by making targeted genetic disruptions that disable a key neurotransmitter receptor in the fruit fly, they have uncovered an important clue to the physiological mechanisms at work in learning and memory. The subject of the study was the so-called NMDA receptor--a neurotransmitter receptor possessing special properties that could make it especially useful in learning and memory. In particular, past work has shown that NMDA receptors can respond in a special way to concurrent events on both sides of a synapse. Acting in this way as "coincidence detectors," NMDA receptors may help neurons form stronger or weaker connections with each other depending on whether they are repeatedly stimulated together. Neuroscientists strongly suspect that this process--called synaptic plasticity--of modulating the strength of synaptic connections on the basis of experience forms an elemental, neuron-level basis for learning and memory. In the new work, the researchers sought to overcome technical hurdles that have stood in the way of understanding when and how NMDA receptors function in learning and memory. The research team, led by Tim Tully of Cold Spring Harbor Laboratory and Ann-Shyn Chiang of National Tsing Hua University, Taiwan, first used a genetic mutation to show that NMDA receptors are required for associative, or Pavlovian, learning in the fruit fly; they then went on to show that these receptors are not just passively participating but are in fact actively needed for both associative learning and long-term memory.

Keyword: Learning & Memory
Link ID: 7173 - Posted: 04.12.2005

CHICAGO – Deep brain stimulation of two different areas of the brain appears to improve problems with uncontrolled movements (dyskinesia) in patients with Parkinson disease (PD), according to an article in the April issue of Archives of Neurology, one of the JAMA/Archives journals. Deep brain stimulation with electrical impulses delivered to structures deep within the brain is being intensively investigated for the management of advanced Parkinson disease, according to background information in the article. Although a number of studies have shown that stimulation of two different areas of the brain, the globus pallidus interna (GPi) and the subthalmic nucleus (STN), can be achieved safely and effectively, STN has been thought to be the preferred target. At the same time, the authors note, there does seem to be some evidence that the STN is more vulnerable during surgery and that STN patients may have more postoperative problems. Valerie C. Anderson, Ph.D., of the Oregon Health and Science University, Portland, and colleagues compared 23 patients with Parkinson disease and problems with medication-induced uncontrolled movement who were randomly assigned to implantation of deep brain stimulators in either the GPi or the STN areas of the brain. Patients' Parkinson symptoms were evaluated with and without medication using a standard rating scale at three, six and 12 months after surgery.

Keyword: Parkinsons
Link ID: 7172 - Posted: 06.24.2010

St. Paul, Minn. – A new study has found no link between use of cell phones and the risk of developing a brain tumor. The study is published in the April 12 issue of Neurology, the scientific journal of the American Academy of Neurology. The Danish study questioned 427 people with brain tumors and 822 people without brain tumors about their cell phone use. The study found no increased risk for brain tumors related to cell phone use, frequency of use, or number of years of use. “These results are in line with other large studies on this question, including a recently published large-scale, population-based study by the Swedish Interphone Study Group,” said study author Christoffer Johansen, PhD, DMSc, MD, of the Danish Cancer Society in Copenhagen. “There have been a few studies that found an increased risk of brain tumors with cell phone use, but those studies have been criticized for problems with the study design.” For 27 people with brain tumors and 47 people without brain tumors, researchers obtained phone records from cell phone companies to document the amount and length of calls and compare the actual calls to what participants reported. Those results found that people accurately remembered the number of calls they made, but did not accurately remember the length of those calls. But there were no differences between the two groups on how well they portrayed their cell phone use. Johansen said that finding minimizes the possibility of what researchers call “recall bias,” or the chance that people with brain tumor may exaggerate or underestimate their past cell phone use.

Keyword: Miscellaneous
Link ID: 7171 - Posted: 06.24.2010

Sarasota, FL - Smell and taste play essential roles in our daily lives. The chemical senses serve as important warning systems, alerting us to the presence of potentially harmful situations or substances, including gas leaks, smoke, and spoiled food. Flavors and fragrances are also important in determining what foods we eat and the commercial products we use. The pleasures derived from eating are mainly based on the chemical senses. Thousands of Americans experience loss of smell or taste each year resulting from head trauma, sinus disease, normal aging and neurological disorders, such as brain injury, stroke and Alzheimer's disease. By providing a better understanding of the function of chemosensory systems, scientific and biomedical research is leading to improvements in the diagnoses and treatment of smell and taste disorders. Some new findings to be presented at the meeting include: Newborn Sense of Smell May Save Life -- Odorization of the incubator prevents apneas in premature infants. Sperm Are Attracted by Chemicals -- Mechanisms of sperm navigation in turbulent flow. Human pheromone receptors -- De-orphaning, functional characterization and cAMP signalling of five human V1R-like receptors. Genetic Odorprints May Use Peptides -- Encoding immune system signals by the mammalian nose: The scent of genetic compatibility. Reduced Selection for Human Odor Receptor Genes -- A genomic perspective on the evolution of olfaction in primates.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 7170 - Posted: 04.12.2005

COLLEGE STATION, - A baby's understanding of language may begin with its own name, which a baby uses to break sentences into smaller parts so it can learn other words, according to new research by Texas A&M University psychologist Heather Bortfeld, who studies language development in infants and children. Bortfeld's research, which appears in the upcoming April issue of "Psychological Science," shows that babies use familiar words such as their names as a sort of "anchor" into the speech stream. A baby as young as six months can learn to recognize an individual word that follows its own name, even after hearing both words as part of whole sentences, says Bortfeld who worked with colleagues from Brown University and the University of Delaware. "Recognition drives segmentation of the speech stream, and segmentation is a critical step in learning a language," Bortfeld explains. "We know from previous research that babies are recognizing their names in fluent speech by the age of six months, so we hypothesized that they should be able to use that recognition to segment the speech stream and recognize new words." Much in the same way a person might have difficulty understanding a foreign language because it's hard to tell where one word starts and another begins, babies face a similar challenge in learning language. Bortfeld's research shows babies can begin to discern the beginnings and endings of words that follow their names, meaning their names form a foundation for learning language.

Keyword: Language
Link ID: 7169 - Posted: 04.12.2005

Women who smoke when pregnant may spark asthma in their grandchildren decades later, a new study discovers. A child whose maternal grandmother smoked while pregnant may have double the risk of developing childhood asthma compared with those with grandmothers who never smoked, say researchers from the University of Southern California, US. And the risk remains high even if the child’s mother never smoked. It has been known for some time that smoking while pregnant can increase the risk of the child developing asthma, but this is the first time that the toxic effects of cigarette smoke have been shown to damage the health of later generations. The researchers believe that the tobacco may be altering which genes are switched “on” or “off” in the fetus’s reproductive cells, causing changes that are passed on to future generations. Frank Gilliland, professor of preventative medicine at the Keck School of Medicine in Los Angeles, US, and colleagues interviewed the parents of 338 children who had asthma by the age of five and a control group of 570 asthma-free children. They found that children whose mothers smoked while pregnant were 1.5 times more likely to develop asthma that those born to non-smoking mothers. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Development of the Brain
Link ID: 7168 - Posted: 06.24.2010

Butterflies do not flutter aimlessly around the garden but instead follow precise flightpaths, scientists say. A UK team of researchers made the discovery by tracking the insects with radar, using tiny transponders attached to the backs of butterflies. This gave them information on the insects' flightpaths, speeds and foraging behaviour - some of which could guide conservation measures. Details of the research appear in Proceedings of the Royal Society B. "We've never been able to see their flight tracks up to 1km before and it's showing us that they do seem to be quite directive in the way they're flying," said co-author Lizzie Cant of Rothamsted Research in Harpenden, UK. The scientists tagged peacock (Inachis io) and small tortoiseshell (Aglais urticae) butterflies with transponders weighing just 12mg. After checking that the devices did not affect their behaviour, the researchers released 33 insects into a 500x400 sq m field being scanned by radar on the Rothamsted estate. This allowed them to track an individual butterfly at a range of up to about 1km. They successfully recorded the movements of 30 of the insects they released. (C)BBC

Keyword: Animal Migration
Link ID: 7167 - Posted: 04.10.2005

COLUMBUS, Ohio – A gene that is changed in many forms of cancer has also been found to show similar changes in some forms of autism, according to preliminary research. The gene, known as PTEN, was found to be changed, or mutated, in three of 18 people with larger than normal heads and autism spectrum disorder. Autism spectrum disorder includes classical autism, Rett syndrome and other conditions. The study was led by researchers at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital (OSU CCC-James) and Richard J. Solove Research Institute and at Children’s Mercy Hospitals and Clinics, Kansas City, Mo. Inherited gene mutations in the PTEN gene are seen in Cowden syndrome, a poorly recognized disorder that increases a person’s risk of developing cancers of the breast, thyroid and uterus. PTEN mutations are also found in several non-inherited (i.e., spontaneous) cancers, including thyroid and endometrial cancers and some brain tumors. The findings, published in the April Journal of Medical Genetics, raise the possibility that some people with autism and large heads may have an increased risk of cancer. “If our findings are verified, I think that patients with classical autism or autism spectrum disorders and who have large heads should be offered genetic counseling and testing for PTEN mutations,” says principal investigator Charis Eng, professor of internal medicine and director of the clinical cancer genetics program at the OSU CCC-James.

Keyword: Autism; Genes & Behavior
Link ID: 7166 - Posted: 06.24.2010

If you've ever stepped out on a 10-meter-high diving platform or wandered down a dark alley, you're probably familiar with the racing heart and sweaty palms that characterize the autonomic nervous system's response to fear. Now, researchers have clarified the molecular underpinning of the brain’s fear response. The findings may point the way to better drugs for people with phobias and other anxiety disorders. Fear responses are controlled by an almond-shaped structure called the amygdala, located deep inside the brain. The amygdala weighs messages sent from many regions of the brain, and when things get sufficiently scary, it triggers the autonomic fear response via "output" neurons located in a subdivision called the central amygdala. In the new study, neuroscientist Daniel Huber at the University of Lausanne, Switzerland, and colleagues used slices of rat brains to take a closer look at the chemical communication signals used by the central amygdala's neurons. They found that vasopressin, a peptide known to boost anxiety and stress, increased the electrical activity of output neurons in one part of the central amygdala, while oxytocin, a peptide with nearly opposite effects on mood, stimulated neurons in an adjacent region. Moreover, neurons stimulated by oxytocin released a neurotransmitter that inhibited the vasopressin-sensitive output neurons. The findings suggest that vasopressin and oxytocin have contrasting influences on behavior because they have opposite effects on the output neurons of the central amygdala, the team reports in the 8 April issue of Science. The researchers speculate that natural variations in the balance of vasopressin and oxytocin receptors in the central amygdala could explain why some individuals are typically nervous, while others are seemingly immune to anxiety. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Emotions; Hormones & Behavior
Link ID: 7165 - Posted: 06.24.2010

New Haven, Conn.-Long-acting injections of the drug naltrexone, combined with psychotherapy, significantly reduced heavy drinking in patients being treated for alcohol dependence, according to a study in the Journal of the American Medical Association by a Yale School of Medicine researcher. "The decision to take medication can wane over time," said Stephanie O'Malley, professor of psychiatry and director of the Division of Substance Abuse Research at the Connecticut Mental Health Center at Yale. "This provides coverage for an entire month." Acohol dependence ranks as the fourth leading cause of disability worldwide, as reported by the World Health Organization's Global Burden of Disease project. Nationwide, it is believed to contribute to more than 100,000 preventable deaths a year. Naltrexone belongs to a class of drugs called opioid antagonists. Although many clinical trials have shown that oral naltrexone can be effective in treating alcohol dependence, its use in clinical practice has been limited, in part patients have to take the pill daily.

Keyword: Drug Abuse
Link ID: 7164 - Posted: 04.10.2005

PORTLAND, Ore. -- An Oregon Health & Science University researcher is among an international team closing in on why many people with schizophrenia and other psychotic disorders are "supersensitive" to the powerful neurotransmitter dopamine. David Grandy, Ph.D., associate professor of physiology and pharmacology, OHSU School of Medicine, co-authored a study appearing recently in Proceedings of the National Academy of Sciences that found a link between dopamine supersensitivity and increased levels of a dopamine receptor with a particularly high affinity for dopamine. Dopamine is a neurotransmitter found in the brain that plays an important role in the regulation of behavior involved in movement control, motivation and reward, and the dopamine system is thought to be essential to the brain's response to drugs of abuse, especially opiates and psychostimulants. Supersensitivity to dopamine, which affects some 70 percent of individuals with schizophrenia, can take the form of a low tolerance to antipsychotics, amphetamines and other drugs, including drugs of abuse, that trigger dopamine's release in the brain. The latest discovery could someday lead to the development of drug therapies that temporarily bring people with psychosis into a more normal, less-sensitive state and make them more amenable to antipsychotic treatment.

Keyword: Schizophrenia; Genes & Behavior
Link ID: 7163 - Posted: 04.10.2005

Christen Brownlee Historian Frank W. Sweet of the University of Florida in Gainesville recounts the classic rags-to-riches tale of Louetta Chassereau, an early 20th-century socialite. As a baby, Chassereau was adopted from an orphanage by a well-to-do white couple. She later married a wealthy man, and her children attended the best white-only schools. However, a dilemma developed when Chassereau's husband died, leaving everything in his will to his beloved wife. Enraged, her husband's relatives contested the will. The reason? Although people in her community had always thought of her as white, "Louetta had started life as a Black baby," says Sweet in a recent essay. Because Chassereau was born of black parents, according to an antimiscegenation law of the time, Chassereau legally could marry only a black man. The white family claimed that she had no right to the fortune. Although the courts ruled in Chassereau's favor in 1940, saying that her life's path had made her "irrevocably white," her in-laws remained unconvinced. In the past 65 years, defining race hasn't become less ambiguous. While it's abundantly clear that race exists from a sociological standpoint—racism wouldn't take place without it—does that categorization also exist biologically? Current genetic research hasn't yet come up with a black-and-white answer. Nevertheless, understanding the biology underlying perceptions of race could have dramatic implications. Copyright ©2005 Science Service

Keyword: Genes & Behavior
Link ID: 7162 - Posted: 06.24.2010

Bruce Bower Two new lines of evidence bolster the claim that the oldest known member of the human-evolutionary family lived in central Africa between 6 million and 7 million years ago. In 2001, at a site in Chad, anthropologist Michel Brunet of the University of Poitiers in France and his coworkers found jaw fragments, isolated teeth, and the nearly complete skull of a creature that the researchers identified as a hominid and assigned to the category Sahelanthropus tchadensis. The skull combines a cranium suitable for a chimp-size brain with facial and tooth structures resembling those of later human ancestors (SN: 7/13/02, p. 19: http://www.sciencenews.org/articles/20020713/fob1.asp). After the discovery, a group of researchers led by Milford H. Wolpoff of the University of Michigan in Ann Arbor initiated a controversy by contending that Sahelanthropus looks more like a fossil ape than a hominid (SN: 10/19/02, p. 253: Available to subscribers at http://www.sciencenews.org/articles/20021019/note12.asp). Brunet's team now reports the discovery of two more jaw pieces and another tooth from Sahelanthropus. The researchers unearthed the specimens in Chad at three locations, including the site of the prior finds. Copyright ©2005 Science Service.

Keyword: Evolution
Link ID: 7161 - Posted: 06.24.2010

Narelle Towie After months roaming the waves as larvae, it seems that fish tune into the sounds of home when they want to settle down. A study on Australia's Great Barrier Reef has shown that the crackle of shrimp and the calls of fellow fish serve to attract tropical tiddlers. Researchers working near Lizard Island, 240 kilometres north of Cairns, Queensland, set up 24 fake reefs made from dead coral. Half the reefs contained submersible speakers that played a cacophony of genuine reef noise consisting of snapping shrimp and other fish. They found that noisy reefs attracted a far greater number of fish than those that were silent. "We knew that they were attracted to light traps. But no one had shown that the fish located sound and could be encouraged to settle depending on it," says Stephen Simpson of the University of Edinburgh, UK, who led the research. Around 80% of the fish attracted to the reefs were cardinalfish (apogonids), and most of the remainder were damselfish (pomacentrids). But noisy reefs also attracted a wide range of less common fish, the researchers report in Science1. ©2005 Nature Publishing Group

Keyword: Hearing
Link ID: 7160 - Posted: 06.24.2010

Just think how eerie it would be, yet also how peaceful - people all around having conversations on their mobile phones, but without uttering a sound. Thanks to some military research, this social nirvana just might come true. DARPA, the US Department of Defense's research agency, is working on a project known as Advanced Speech Encoding, aimed at replacing microphones with non-acoustic sensors that detect speech via the speaker's nerve and muscle activity, rather than sound itself. One system, being developed for DARPA by Rick Brown of Worcester Polytechnic Institute in Massachusetts, relies on a sensor worn around the neck called a tuned electromagnetic resonator collar (TERC). Using sensing techniques developed for magnetic resonance imaging, the collar detects changes in capacitance caused by movement of the vocal cords, and is designed to allow speech to be heard above loud background noise. DARPA is also pursuing an approach first developed at NASA's Ames lab, which involves placing electrodes called electromyographic sensors on the neck, to detect changes in impedance during speech. A neural network processes the data and identifies the pattern of words. The sensor can even detect subvocal or silent speech. The speech pattern is sent to a computerised voice generator that recreates the speaker's words. © Copyright Reed Business Information Ltd

Keyword: Language
Link ID: 7159 - Posted: 06.24.2010

Drinking a glass or two of milk a day may raise the risk of Parkinson's disease in middle-aged men, research suggests. Researchers say the apparent link is unlikely to be anything to with calcium - milk's key nutritional ingredient. But they say it is unclear whether another ingredient, or a contaminant may raise the risk of Parkinson's - which overall still remains low. The study, led by Korea University, is published in the journal Neurology. Parkinson's disease is a degenerative disease of the nervous system associated with trembling of the arms and legs, stiffness and rigidity of the muscles and slowness of movement. Previous research has also suggested a link between high consumption of dairy products and a raised risk of Parkinson's in men - but not women. The latest study focused on 7,504 men aged 45 to 68, who were enrolled in a heart study in Hawaii. During the course of the 30-year study, 128 developed Parkinson's. The researchers found those men who consumed more than 16oz (454g) of milk a day were 2.3 times more likely to develop Parkinson's than those who drank no milk at all. Overall, the risk of Parkinson's - even among men who drank a lot of milk - was low. The researchers calculated that in each 12 month period 6.9 cases of Parkinson's could be expected per 10,000 people who drank no milk. Among those who drank more than 16ozs a day the figure was 14.9 per 10,000. However, they found no evidence of a link between calcium consumption and Parkinson's. (C)BBC

Keyword: Parkinsons
Link ID: 7158 - Posted: 04.07.2005