Friday 14 November 2014

Neuroscientists speak out against brain game hype | Science/AAAS | News

Neuroscientists speak out against brain game hype | Science/AAAS | News:

Neuroscientists speak out against brain game hypeAging baby boomers and seniors would be better off going for a hike than sitting down in front of one of the many video games designed to aid the brain, a group of nearly 70 researchers asserted this week in acritique of some of the claims made by the brain-training industry. 

With yearly subscriptions running as much as $120, an expanding panoply of commercial brain games promises to improve memory, processing speed, and problem-solving, and even, in some cases, to stave off Alzheimer’s disease. Many companies, such as Lumosity and Cogmed, describe their games as backed by solid scientific evidence and prominently note that neuroscientists at top universities and research centers helped design the programs. But the cited research is often “only tangentially related to the scientific claims of the company, and to the games they sell,” according to the statement released Monday by the Stanford Center on Longevity in Palo Alto, California, and the Max Planck Institute for Human Development in Berlin.
Although the letter, whose signatories include many researchers outside those two organizations, doesn’t point to specific bad actors, it concludes that there is “little evidence that playing brain games improves underlying broad cognitive abilities, or that it enables one to better navigate a complex realm of everyday life.” A similar statement of concern was published in 2008 with a smaller number of signatories, says Ulman Lindenberger of the Max Planck Institute for Human Development, who helped organize both letters. Although Lindenberger says there was no particular trigger for the current statement, he calls it the “expression of a growing collective concern among a large number of cognitive psychologists and neuroscientists who study human cognitive aging.”
“A major problem” with almost all cognitive training studies is that researchers only measure improvement in skills such as memory based on an individual task, rather than a range of tasks that represent a broad ability, Lindenberger says. Although a handful of the researchers who signed the letter are involved in brain-training game research and development themselves, all signees “draw a clear line” between improvements on a particular task and improvements in general cognitive ability, he notes. In contrast, “brain gaming companies blur this distinction,” he says, leading consumers to believe that getting better at a specific game will positively impact their cognitive abilities and competence in everyday life. “The consensus is that this is not so,” he notes.
Not all researchers agree, however. Lumping all brain game companies together and calling their claims dubious is “a classic case of throwing out the baby with the bathwater,” said Michael Merzenich, a professor emeritus of neuroscience at the University of California, San Francisco, and chief scientific officer of the brain-training company Posit Science, to The Chronicle of Higher Education, describing the statement as “irresponsible.”
Roberto Cabeza, a neuroscientist at Duke University in Durham, North Carolina, and another signatory on the statement, says that his view is that it’s fine to play such games for fun, but “if you’re doing it like a chore” to postpone cognitive aging and dementia there are other, better established methods of keeping the brain sharp, such as exercising. Cognitive improvements from exercise appear to be modest, but are still greater than any of the small, fleeting gains yet observed in studies of gaming, he says. There are also health benefits to exercise that cannot be achieved by sitting at a computer, he adds. In addition to showing that brain games have benefits that transfer to daily life, “you also have to compare it to what you could have done during those hours,” such as playing an instrument or spending time with family, he says.
For those who choose to play brain games regardless, recent research suggests that playing some video games developed solely for fun may be as effective, or more, than those developed for cognitive self-improvement. Scientists at Florida State University randomly assigned 77 undergraduates to play either Lumosity or the popular video game Portal 2, in which players take on the roles of robots to solve interactive puzzles to face off against a “lethally inventive, power-mad A.I. named GLaDOS.” After 8 hours of play, Portal 2 players scored higher than Lumosity players on three standard cognitive tests of problem-solving and spatial skill, and Lumosity players “showed no gains on any measure,” the team reported online this summer inComputers & Education.

Thursday 13 November 2014

Regular marijuana habit changes your brain, study says - CNN.com

Regular marijuana habit changes your brain, study says - CNN.com:

By Saundra Young and Matthew Stucker, CNN
November 11, 2014 -- Updated 1447 GMT (2247 HKT)
STORY HIGHLIGHTS
  • Study of long-term marijuana users finds they have smaller decision-making area of brain
  • Chronic marijuana users had an IQ 5 points lower than those who did not use
  • Some scientists say this study shows marijuana is not "a harmless drug"
(CNN) -- Using marijuana at an early age could have long-term consequences on your brain and it may even lower your IQ, according to a new study in the Proceedings of the National Academy of Sciences.
Researchers found that compared to nonusers, people who smoked marijuana starting as early as age 14 have less brain volume, or gray matter, in the orbitofrontal cortex. That's the area in the front of your brain that helps you make decisions.
"The younger the individual started using, the more pronounced the changes," said Dr. Francesca Filbeythe study's principal investigator and associate professor at the School of Behavioral and Brain Sciences at the University of Texas at Dallas. "Adolescence is when the brain starts maturing and making itself more adult-like, so any exposure to toxic substances can set the course for how your brain ends up."


Photos: History of marijuana in AmericaPhotos: History of marijuana in America
Researchers also found increased brain connectivity in chronic users. Connectivity, when different parts of the brain connect to each other, is important for adaptive learning abilities. It also helps your mind make associations. This wiring of the brain starts to deteriorate with chronic marijuana use.


Source: NYC marijuana policy to change


Colorado's booming marijuana industry
"Too much or too little of anything isn't good. There needs to be an equal balance," said Filbey.
There were 48 marijuana users enrolled in this study. All started smoking between age 14 and 30. The average age of the person enrolled in the study was 18. On average they used marijuana three times a day. Most said they had been using it for 10 years, although some had been smoking pot for three decades.
Scientists compared this group to a group of 62 nonusers of the same basic age and gender. All gave urine samples. All had an MRI scan and all went through IQ testing.
Filbey said the people who regularly used marijuana had IQ's that were five points lower, on average, than the nonusers in the study, although there is no definitive proof that marijuana alone was to blame for the lower IQ.
"While our study does not conclusively address whether any or all of the brain changes are a direct consequence of marijuana use, these effects do suggest that these changes are related to age of onset and duration of use," Filbey said.
Dr. Susan Weiss, associate director for Scientific Affairs at the National Institute on Drug Abuse said the study provides more strong evidence about the dangers of marijuana.
"This is a complex and interesting study that adds to the growing body of evidence that heavy marijuana use, particularly at a young age, is linked to significant adverse brain changes," said Weiss. "This study showed that the orbitofrontal cortex, an area involved in reward, decision making and motivation, was smaller in heavy users and that other brain circuits were enhanced, likely to compensate for the diminished function in that region. Further prospective studies are needed to clarify this, but these mounting scientific findings certainly challenge the widespread belief that marijuana is a harmless drug."
The National Institute on Drug Abuse helped fund the study.
Mason Tvert, director of communications for the Marijuana Policy Project, said marijuana use does not cause IQ loss.
"Once again, researchers have failed to find any conclusive evidence that marijuana use causes mental health problems. The researchers note their findings are nonconclusive, that they might be skewed by other factors, and that effects, if any, could be temporary, Tvert said. "The study doesn't justify keeping marijuana illegal, nor does it say anything about making it legal. There remains no doubt that marijuana is far less harmful than alcohol to the brain and to the rest of the body. The possibility that marijuana might have some harm for some people -- but might not -- is not a good reason to keep arresting and punishing hundreds of thousands of adults simply for using it."
Filbey next plans to do long-term observational studies with people who do not use marijuana to see if there are underlying factors like pre-existing conditions before exposure to THC, the psychoactive ingredient in cannabis, that could account for some of these effects.