Children who use marijuana before age 12 are twice as likely to later develop serious mental illness as those who don't try the drug until they're 18, according to a federal report released Tuesday.
Study says many use chemicals linked to fertility problems
Dozens of common household cleaning products contain hidden toxic chemicals linked to fertility disorders in lab animals, according to data gathered by a women's research group.
The first study to examine brain activity patterns in severely traumatized children showed their brains function differently than those of healthy children, say researchers at the Stanford University School of Medicine and Lucile Packard Children's Hospital.
The study hints at the biological underpinnings of the disorder called PTSD, or post-traumatic stress disorder. It also provides a valuable benchmark with which to assess the effectiveness of potential therapies.
"Now we can see some real neurological reasons for the impulsivity, agitation, hyper-vigilance and avoidance behaviors that children with untreated PTSD often exhibit," said Victor Carrion, MD, child psychiatrist at Packard Children's. "The fact that their brains appear to be working differently may indicate a deficit for which other areas of the brain are trying to compensate."
Some children with PTSD, for example, cut or burn themselves as a way of coping with their feelings. The researchers found that affected children who had also cut or otherwise injured themselves exhibited unique patterns of activation in a portion of the brain involved in the perception of pain and emotions.
It's not yet clear whether the brain differences are caused by the interpersonal trauma, such as sexual or physical abuse, experienced by the children or if pre-existing differences make some children more susceptible to developing PTSD after traumatic events than their more resilient peers.
As the $20 billion organic marketplace continues to expand, major corporations continue to take over many of the most familiar organic brands. Dr. Phil Howard, an Assistant Professor at Michigan State, has provided a new update on his popular chart "Who Owns Organic." Are you supporting corporations like Kraft, M&M, or Pepsi with what you thought was a purchase of your old familiar brand?
The capacity to resist peer pressure in early adolescence may depend on the strength of connections between certain areas of the brain, according to a study carried out by University of Nottingham researchers.
New findings suggest that enhanced connections across brain regions involved in decision-making may underlie an individual's ability to resist the influence of peers.
The study, published in the July 25 issue of The Journal of Neuroscience, suggests that brain regions which regulate different aspects of behaviour are more interconnected in children with high resistance to peer influence.
Professor Tomas Paus and colleagues at The University of Nottingham used functional neuroimaging to scan adolescents while they watched video clips of neutral or angry hand and face movements. Previous research has shown that anger is the most easily recognised emotion.
In a new study from the August issue of the Journal of Consumer Research, researchers from Northwestern University demonstrate how advertisements can be manipulated to cause overemphasis of a particular feature and increase the likelihood that a certain product is chosen. Their finding runs contrary to economic models, which assume that choices are based on stable preferences and should not be influenced by the inclusion of inferior options.
"By showing the impact of perceptual focus on consumer preferences, this research demonstrates that in addition to the many overt ways companies can draw attention to products, the visual arrangement of alternatives can also have a significant influence on their relative choice shares," explain Ryan Hamilton, Jiewen Hong, and Alexander Chernev.
In a series of fascinating experiments, the authors show how grouping together options with similar characteristics can emphasize dissimilar options and help them pop-out. For example, consider a comparison of two sofas, A and B. Sofa A has softer cushions; Sofa B is more durable. In a head-to-head comparison, sofa A is preferred by less than half of the survey participants - 42.3 percent.
Think you haven't got the aptitude to learn a foreign language? New research led by Northwestern University neuroscientists suggests that the problem, quite literally, could be in your head.
"Our study links brain anatomy to the ability to learn a second language in adulthood," said neuroscientist Patrick Wong, assistant professor of communication sciences and disorders at Northwestern and lead author of a study appearing online today (July 25) at , in Cerebral Cortex.
Based on the size of Heschl's Gyrus (HG), a brain structure that typically accounts for no more than 0.2 percent of entire brain volume, the researchers found they could predict -- even before exposing study participants to an invented language -- which participants would be more successful in learning 18 words in the "pseudo" language.
Wong and his colleagues measured the size of HG, a finger-shaped structure in both the right and left side of the brain, using a method developed by co-authors Virginia Penhune and Robert Zatorre (Montreal Neurological Institute). Zatorre and Penhune are well known for research on human speech and music processing and the brain.
"We found that the size of left HG, but not right HG, made the difference," said Northwestern's Catherine Warrier, a primary author of the article titled "Volume of Left Heschl's Gyrus and Linguistic Pitch." Anil K. Roy (Northwestern), Abdulmalek Sadehh (West Virginia University) and Todd Parish (Northwestern) also are co-authors.
A bedrock assumption in theories that explain and predict human behavior is people's motivation to pursue pleasure and avoid pain. How can this be reconciled with the decision to engage in experiences known to elicit negative feelings, such as horror movies" It certainly seems counterintuitive that so many people would voluntarily immerse themselves in almost two hours of fear, disgust and terror. "Why do people pay for this?" "How is this enjoyable?"
Investigators generally use one of two theories to explain why people like horror movies. The first is that the person is not actually afraid, but excited by the movie. The second explanation is that they are willing to endure the terror in order to enjoy a euphoric sense of relief at the end. But, a new study by Eduardo Andrade (University of California, Berkeley) and Joel B. Cohen (University of Florida) appearing in the August issue of the Journal of Consumer Research argues that neither of these theories is correct.
"We believe that a reevaluation of the two dominant explanations for people's willingness to consume "negative" experiences (both of which assume that people can not experience negative and positive emotions simultaneously) is in order," explain Andrade and Cohen in their study.
Thu, 26 Jul 2007 05:06 UTC
Working for long periods in the harsh and unforgiving conditions near the North Pole and South Pole often causes people to suffer a stew of psychological symptoms dubbed "polar madness," scientists said yesterday.
The researchers studied the psychological effects on people from toiling in remote polar outposts, often for a year at a time, gleaning lessons they say might help prepare for lengthy human space missions, such as a trip to Mars.
While some people on polar expeditions savor a gratifying sense of achievement, the researchers said, 40 percent to 60 percent of them may suffer negative effects such as depression, sleep disruption, anger, irritability, and conflict with co-workers.
Thu, 26 Jul 2007 04:13 UTC
Many people believe potentially harmful myths about epilepsy, a study from University College London suggests.
A third would put something in the mouth of a person having a seizure to stop them swallowing their tongue - but doing so could block their airways.
And 67% of the 4,605 people asked would call an ambulance immediately, Epilepsy and Behavior journal reports.
This is only needed for first seizures, those lasting over five minutes, if the person is hurt or has several seizures.