Picture the classic shoot-out in a Western movie: The good guy and the bad guy face each other, their hands quivering over their gun holsters. The bad guy reaches for his weapon, causing the good guy to react–he whips out his pistol and BAM! The hero triumphs. Physicist Niels Bohr once had a theory on why the good guy always won shoot-outs in Hollywood westerns. It was simple: the bad guy always drew first. That left the good guy to react unthinkingly – and therefore faster. When Bohr tested his hypothesis with toy pistols and colleagues who drew first, he always won [New Scientist].
But new research suggests that Bohr didn’t have it exactly right. In a study published in Proceedings of the Royal Society B, scientists suggest that people do move faster when they are reacting to what is happening around them–but not fast enough for a heroic gunslinger to save his own life.
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It wasn’t quite as dramatic as a slow-motion movie action sequence or a slo-mo instant reply, but researchers have successfully slowed down people’s manipulation of a computer joystick by boosting one type of brain wave. The researchers generated a small electrical current in the brains of 14 healthy volunteers using scalp electrodes. The current increased the activity of normal beta waves [New Scientist], and slowed the volunteers’ reaction times by 10 percent. The study, published in Current Biology, has implications for Parkinson’s Disease, in which patients have trouble with voluntary motions.
Brain waves are generated naturally when groups of neurons fire in a certain rhythm. Lead researcher Peter Brown explains that the low-frequency beta waves were already known to play a role in movement. “Different parts of the brain work together and generate certain frequencies,” he explained, “and the movement areas of the brain come together in beta activity. That activity is suppressed just prior to and during movement, so we think the body gets rid of it to prepare to make a new movement” [BBC News].
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Inserting a “pacemaker” into the brain to emit regular pulses of electricity and quell disordered neural activity may sound like a therapy of last resort, but if current experiments show beneficial results the brain surgery may one day be commonplace. But some scientists are cautioning that research on so-called deep brain stimulation may be pressing ahead too quickly, and warn that long-term effects of the surgery are not yet clear.
A growing number of psychiatric researchers are testing the method’s effectiveness on a host of psychiatric disorders. Until recently, deep brain stimulation was approved in the U.S. only to treat certain movement disorders, primarily those of Parkinson’s disease, for which it diminishes tremors and rigidity and improves mobility. To date, more than 60,000 patients worldwide have had the devices implanted [Los Angeles Times]. But now large clinical trials are in the works that will test the use of deep brain stimulation for obsessive compulsive disorder, epilepsy, and depression. Smaller experiments are beginning to assess the therapy’s effectiveness on a wide range of disorders including anorexia, drug addiction, obesity, traumatic brain injury, and Alzheimer’s.
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Parkinson’s patients could one day find relief from their symptoms by wearing a device on the backs of their necks that sends steady pulses of electricity up their spinal cords and into their brains, according to a new study. Researchers tested the technology on lab rats and mice that were nearly immobilized with Parkinson’s-like symptoms, and saw an immediate and dramatic effect. As long as a mild current flows up their spines and into their brains, the animals regain the ability to scamper around their cages, as if they were normal…. [Lead researcher Miguel] Nicolelis added that the procedure was now being tested on monkeys, and “if it succeeds, human clinical trials could begin in the next few years” [The New York Times].
Some Parkinson’s patients have already found relief from their symptoms with deep brain stimulation, in which tiny electrodes are surgically implanted in their brains to make a “brain pacemaker,” but this new experiment was the first to try a less invasive form of neural stimulation. If the findings are confirmed in humans, scientists say, the procedure could dramatically improve treatment for the disease by making electrical therapies safer and more broadly available [Technology Review].
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Playing true to form, Google cofounder Sergey Brin is launching an ambitious, expensive effort using unorthodox tactics, but this time he’s taking on Parkinson’s research. In cooperation with the personal genetics testing company 23andMe, which was cofounded by Brin’s wife, Anne Wojcicki, Brin is hoping to get 10,000 Parkinson’s patients to fill out online questionnaires and get their genomes scanned. To encourage participation, 23andMe will provide the DNA scan for $25, a fraction of the normal $399 price. Brin, who says he has an elevated risk of Parkinson’s, will contribute the bulk of the money for the study, although he declined to disclose the total costs.
Wojcicki says that getting full genetic information for so many patients could reveal genetic patterns to the disease, which has already been linked to a handful of genes. “We want to try and find out if there are other genetic variations that are associated with Parkinson’s or with rapid progression or slow progression,” said Wojcicki, in a telephone interview yesterday. “Also, why some people respond well to therapy, some people don’t, and some develop resistance faster” [Bloomberg].
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Implanting a pacemaker-like device in the brains of Parkinson’s patients improves their condition significantly more than medication and physical therapy, a new study has found. The implantation of a deep brain stimulation device gave patients almost five additional hours each day when they were untroubled by the tremors, jerking limbs, and rigidity that characterize Parkinson’s, a movement disorder. But the surgery carries risks: The deep brain stimulation patients also had almost four times the risk of suffering a serious adverse event like depression, infections, falls or heart problems. Although most side effects could be treated, one patient suffered a brain hemorrhage and died [Chicago Tribune].
The electrodes that doctors install — one on each side of the brain — are actually small, insulated wires that are connected to another wire that runs under the skin to a small battery beneath the skin of the torso. The electrodes are implanted into a part of the brain that normally acts as a relay station for messages. In Parkinson’s patients, a flurry of signals jam this message center, sending aberrant signals to muscles and causing tremors, muscle rigidity, paralysis and other problems. The electrodes send out a mild current that inhibits the stream of messages, relieving the clutter and calming muscle problems [Science News]. The procedure has been an accepted treatment for Parkinson’s since regulators first approved it in 1997, but this study is one of the first to systematically compare the surgery’s results to outcomes from other treatments.
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