Back and forth go the studies investigating whether cell phone uses increases the risk of brain cancer (the latest one to get major press, released last month, found nothing there). This week, though, new research has grabbed the headlines by declaring that our ubiquitous communication and time-wasting devices could actually provide a health benefit.
In a study set to come out today in the Journal of Alzheimer’s Disease (and funded in part by the National Institute on Aging), a group led by Gary Arendash argues that the radiation from cell phones that we’ve been worrying about could protect against Alzheimer’s Disease. But it’s far too soon to advise people to start medicating themselves by talking even longer on the phone.
Researchers at the Florida Alzheimer’s Disease Research Center arranged about 70 mouse cages in a circle around a central antenna that emitted electromagnetic waves typical of what would emanate from a phone pressed to a human head. They were exposed to the radiation for two hours a day over seven to nine months. About two dozen other mice served as controls [Los Angeles Times]. Arendash’s team used mice they had genetically engineered to develop the brain buildups and memory problems typical of Alzheimer’s when they got older. The team says that the memory problems of those mice exposed to the radiation began to disappear during the study. Not only that, but normal mice (that hadn’t been genetically engineered) also showed memory improvements after exposure.
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This week, a eight-year double-blind study of the nutritional supplement ginkgo biloba finally reached the pages of the Journal of the American Medical Association. Many health food stores sell ginkgo supplements to people who are hoping to improve their wits and memory, and particularly to elderly people worried about cognitive decline and dementia. But the conclusion by lead researcher Steven DeKosky? Save your money.
In the GEM [Ginkgo Evaluation of Memory] study, participants aged 72-96 years with little or no cognitive impairment were recruited from four communities in the eastern United States and received either a twice-daily dose of 120-milligrams of extract of G biloba or an identical-looking placebo [AFP]. For the more than 3,000 study participants, researchers found no difference in age-related cognitive decline—including the incidence of dementia or Alzheimer’s—between ginkgo takers and placebo takers.
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One year ago today, a brain-damaged man died peacefully at the age of 82, and neuroscientists the world over learned the identity of the man who was referred to in the textbooks only as “H.M.” Henry Gustav Molaison lost much of a brain structure called the hippocampus during an operation in the 1950s. The procedure was meant to stop his epileptic seizures. However, the hippocampus is critical to memory formation, so the surgery left Molaison unable to form new long-term memories [New Scientist]. By studying Molaison’s behavior over decades, researchers learned an enormous amount about memory formation.
Today, researchers at The Brain Observatory in San Diego are taking the next step in studying the workings of Molaison’s brain: They’re slicing it up. During Molaison’s life, he and his guardian agreed that his brain should be donated to science upon his death. So his brain was frozen, and beginning today it will be cut into about 2,600 very thin slices (think deli meat). Each slice will be photographed, and many will be studied microscopically to determine exactly which parts of Molaison’s brain were damaged in that long-ago operation. The slicing operation, which began about an hour ago, is being streamed live on the Internet, although it’s hardly a gripping action sequence (it looks more like scientists going about their business in a lab). In addition, the photos of the brain slices will soon be posted online for all the world to marvel at.
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Amid mounting evidence that sleep is key for your memory, researchers published a paper in the journal Science last week suggesting that playing specific sounds while a person sleeps—sounds connected to something that the person is trying to memorize—could help the memory sink in.
The researchers taught people to move 50 pictures to their correct locations on a computer screen. Each picture was accompanied by a related sound — meow for a cat, whirring for a helicopter, for example [The New York Times]. Next the test subjects lay down for a nap, and while they slept the researchers played sounds relating to half the objects. When the subjects woke up, scientists tested them on how well they remembered where each object went. Participants didn’t know they’d been subjected to the sounds while they napped, but they fared better at placing the objects for which they heard sounds in their sleep than those they didn’t.
Lead researcher Ken Paller explains: “While asleep, people might process anything that happened during the day — what they ate for breakfast, television shows they watched, anything…. But we decided which memories our volunteers would activate, guiding them to rehearse some of the locations they had learned an hour earlier” [U.S. News & World Report].
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Scientists who have been investigating the link between professional football and severe brain damage have a troubling new piece of evidence: The brain of a deceased man who stopped playing football after college also showed the distinctive signs of damage. The man, the former Western Illinois wide receiver Mike Borich, died at 42 of a drug overdose in February after a downward spiral of depression and substance abuse that is generally associated with the type of tissue damage found in his brain [The New York Times].
The findings suggest that the damage isn’t only associated with professional football players who have played at the highest level of competition for years, but might be a fundamental byproduct of the sport itself. The cumulative effect of the many blows to the head that many football players experience may simply be too much for the brain to handle, researchers say.
Several neuroscientists have been investigating football players with a condition called chronic traumatic encephalopathy (C.T.E.). Scientific progress is slow because the condition can only be diagnosed after death, when the brains donated by players can be sliced, stained, and examined for protein deposits and fibrous tangles. So far, researchers have identified C.T.E. in eight NFL players who died between the ages of 36 and 52–many of whom had extreme emotional problems in their last years. It has been found in every player of those ages examined by the two groups doing such research [The New York Times].
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Researchers have found a pharmaceutical way to clear some of the cognitive fog that results from a sleepless night. In a new study using lab mice, researchers corrected the memory problems in sleep-deprived mice through a drug that suppressed levels of a certain enzyme in a brain region called the hippocampus, which plays an important role in memory and learning.
The study, published in Nature, helps tease out the specific effects of sleep deprivation on the brain. Says lead researcher Christopher Vecsey: “One of the main problems is that sleep deprivation does a lot of things to the brain, and it’s easy to get caught in a mish-mash of different effects” [Nature News].
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It sounds like a scene from an insect version of Total Recall: Using genetically engineered fruit flies and laser beams, researchers have found a way to embed false, fearful memories in the flies.
Researchers first tested normal flies in a chamber where a jets of air on either side brought two different odors into the container. The researchers delivered an electric shock each time a fly strayed into a particular odour stream, which taught the flies to prefer the other one: the flies learned to move in the direction of the shock-related odour 30 per cent less often [New Scientist].
Next, the researchers created a strain of genetically engineered flies with certain neurons that would be activated by a laser blast. Lead researcher Gero Miesenböck explains that with this technique, called optogenetics, researchers can use light to activate particular cell types that have been genetically engineered to express a light-responsive protein. When laser pulses hit the brain, cells expressing the light-sensitive protein activate. “It’s like sending a radio signal to a city but only those houses with a radios set to the right frequency will get the signal,” says Miesenböck [Nature News].
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Sleep deprivation. Stress positions. Waterboarding. These interrogation techniques used by the Bush administration in the war on terror were explained, at the time, as harsh but necessary tactics that forced captives to give up names, plots, and other information. But a new look at the neurobiological effects of prolonged stress on the brain suggests that torture damages the memory, and therefore often produces bad intelligence.
Irish neuroscientist Shane O’Mara reviewed the scientific literature about the effect of stress on memory and brain function after reading descriptions of the CIA’s Bush-era interrogation methods. The methods were detailed in previously classified legal memos released in April. O’Mara did not examine or interview any of those interrogated by the CIA [AP].
His findings: “These techniques cause severe, repeated and prolonged stress, which compromises brain tissue supporting memory and executive function” [Wired.com]. The study, to be published in the journal Trends in Cognitive Sciences, took note of the effect of the stress hormone cortisol on the brain, as well as the fear-related hormone noradrenaline’s impact on memory and the ability to distinguish true from false.
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Some coma patients who appear to be completely unresponsive to the outside world are still capable of the most basic kind of learning, according to a small new study. Researchers found that both vegetative and “minimally conscious” patients were capable of a Pavlovian response, learning to associate a noise with a slightly unpleasant stimulus.
The researchers built on the work of 19th-century Russian psychologist Ivan Pavlov, who famously conditioned his dogs to salivate at the ring of a bell by associating the sound with the presentation of food. In this case, they sounded a tone, which was followed about 500 milliseconds later with a light puff of air to the eye [Scientific American]. At first the patients only responded after the puff of air by blinking or twitching or flinching. But after repeated trials, 15 of the 22 patients began to blink or flinch immediately after the tone sounded, before the puff of air. Electrodes by their eyes picked up the subtle muscle movements.
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A person can witness an event in real life, see a doctored video of the same event, and then convince themselves that what they saw on the video is what actually happened, according to a recent study that casts doubt on the reliability of eyewitness testimony.
Psychologists set up an experiment where they filmed two people sitting side by side–one experimental subject and one researcher pretending to be a participant–playing a gambling game where they bet phony money on whether or not they could answer multiple choice questions correctly. They were told that the person with the most money at the end would win a prize.
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You may remember more than your conscious brain knows, according to a nifty new study that will soon be published in the journal Neuron. Researchers gave college students memory tests while closely monitoring both their eye movements and their brain activity, and found that certain patterns revealed that a student was retrieving the memory of the right answer–although his conscious brain often never got it.
In the experiment, researchers presented a long sequence of pictures of faces paired with an outdoor scene, and finally showed the subject one landscape photo along with three faces, asking him to pick out the face that had originally be paired with the landscape. Immediately, activity in the brain region called the hippocampus increased, followed 500 to 750 milliseconds later by eye movements directed toward one of the three faces. When the hippocampus was more active, the eyes lingered on the correct face. Less hippocampus activity occurred when the eyes dwelled on an incorrect face…. The results suggest that eye movements can reveal unconscious memories activated in the hippocampus [Science News]. This pattern stayed the same regardless of whether the subject ultimately settled on the right answer.
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During both work hours and leisure time, a growing number of people have become extravagant multitaskers, flitting between Web browsing, texting, emailing, and maybe even throwing in some old-fashioned television or print media for good measure. But a surprising new study has found that those who multitask the most are far worse at it than those people who focus on fewer tasks simultaneously. Says study coauthor Clifford Nass: “The huge finding is, the more media people use the worse they are at using any media. We were totally shocked” [AP].
The researchers compared high- and low-multitaskers on a variety of psychological tests, according to the study published in the Proceedings of the National Academy of Sciences. They found that the high-multitaskers were worse at ignoring irrelevant information, worse at organizing information, and took more time to switch between tasks. That final finding particularly surprised the researchers, considering the need to switch from one thing to another in multitasking. “They couldn’t help thinking about the task they weren’t doing,” lead author Eyal Ophir said [AP].
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In the hopes of combating rising suicide and mental illness rates, the U.S. Army is implementing a mental stress training course for all 1.1 million members of the National Guard, reservists, and active-duty soldiers.
The training, the first of its kind in the military, is meant to improve performance in combat and head off the mental health problems, including depression, post-traumatic stress disorder and suicide, that plague about one-fifth of troops returning from Afghanistan and Iraq [The New York Times]. The program will be taught by Army sergeants in classes that generally last about an hour-and-a-half, and will begin in October at two bases before spreading to all service members. The training will also be available for family members and civilian employees.
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Chronically stressed rats make decisions based on habit, new research has shown, even when those habits no longer produce the maximum benefit. Researchers say the stressed out rats’ inability to adapt to changing circumstances seems similar to the human response to chronic stress. How often do we talk about burned-out people who are just going through the motions? [ABC News]
In the study, published in Science, the researchers subjected the rats to several tests. In one experiment, the rats were trained to press a lever to receive a reward (either food pellets or sucrose). After two weeks of training, they were given full access to the reward and allowed to consume as much as they desired. When presented with the lever again, control animals stopped pressing the lever, but stressed animals didn’t. If you get the dessert for free, [study coauthor Rui] Costa said, there’s no need to work for it. “That’s what control animals do,” but stressed animals work anyway [The Scientist].
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A new study based on neurological data and brain specimens from a group of nuns, known as the Nun Study, confirms that language skills earlier in life are linked to Alzheimer’s disease risk in older age. But it also adds new, puzzling information to our knowledge about the disease: The brains of the women who did not have Alzheimer’s symptoms had larger brain cells, or neurons, but not necessarily fewer of the plaques and tangles characteristic of the disease.
To assess language skills early in life, researchers examined essays written by 14 women when they entered the convent, looking for the number of ideas expressed in every group of 10 words. A previous study linked grammatically complex writing skills to a decreased risk of dementia, and this study confirmed it: The essays written by women who maintained their memory scored 20 percent higher on language tests. “This is the second independent sample with the same result. We’re back to the metaphor of the brain as a computer and a muscle,” said [geriatric psychiatrist] Dr. Gary J. Kennedy…. “In volunteers who had no signs of Alzheimer’s but did have the plaques and tangles, the neurons were actually larger and more functional with more connections” [U.S. News and World Report].
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