Saturday, August 30, 2008

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SHEEHAN

Suicides among people with schizophrenia are a major public-health concern in China, according to a new report. One-tenth of all Chinese people who kill themselves suffer from this severe mental disorder, say psychiatrist Michael R. Phillips of Beijing Hui Long Guan Hospital and his coworkers. In most other countries with suicide statistics, schizophrenia accounts for a smaller proportion of the deaths.

China is the only nation studied in which a larger proportion of women than men develops schizophrenia and commits suicide, the researchers report in the Sept. 18 Lancet. People with schizophrenia in China's rural villages kill themselves far more frequently than do those in the cities, the team notes.

Schizophrenia-related suicides in China often involve married women with no previous psychiatric treatment. In Western countries, it's more common for men with schizophrenia to kill themselves shortly after being admitted to a psychiatric hospital.

About 1 in 250 Chinese citizens develops schizophrenia, compared with approximately 1 in 100 U।S. residents, the investigators say. http://louis-j-sheehan.info

The team's portrayal of schizophrenia and suicide in China derives from analyses of a 1993 national psychiatric survey, a national review of suicides recorded between 1995 and 2000 that included psychiatric interviews of surviving families and friends, and government data on mortality trends.http://louis-j-sheehan.info

collaberaTION

Older adults often find that their memories betray them. A team of Canadian psychologists, led by Michael Ross of the University of Waterloo in Ontario, offers this advice to elderly individuals with memory concerns: Don't go it alone.

Talking about recent memories with someone else, such as a spouse, works like a cognitive vacuum cleaner, in Ross' view. It sucks up many mistakes that litter memory, leaving behind a relatively clean core of accurately recalled information.

"Collaboration could help to reduce the frequency of older people's false recall in many everyday contexts," Ross says. Few researchers have examined collaborative remembering (SN: 9/13/97, p. 174).

Ross and his coworkers devised two memory tasks for 59 married couples, ages 68 to 78. The researchers randomly assigned 29 couples to collaborate on their choices and 30 to deliberate individually.

The first task involved list memory. Each couple jointly circled 25 items for purchase in a 70-item grocery catalog. About an hour later, participants were taken to a supermarket where they attempted to remember items from their shopping lists and put them into a cart. After returning home, volunteers again tried to recall items on their shopping lists.

On the second task, participants tried to name 14 highlighted but unlabeled landmarks on a map of their community.

Individuals correctly recalled about two or three more shopping items and landmarks than couples did, the researchers report in the September Applied Cognitive Psychology. However, couples usually made four or five fewer memory errors on these tasks than individuals did.

Collaborators challenged each other's mistakes, Ross theorizes. Consistent with that scenario, individuals working alone rarely picked the same wrong grocery items or made the same landmark errors as their spouses did.

Not surprisingly, when working individually, people with either lots of shopping experience or community familiarity remembered more material on these respective tasks than their less-knowledgeable spouses did. Yet the "experts" and "nonexperts" committed the same number of memory errors, Ross says.

Experts in each area drew on a rich store of memories that generated both hits and misses, he proposes. So, even for an expert, a collaborator can help weed out mistakes.

Collaboration represents a "manageable and realistic solution to a memory problem that gets increasingly onerous as we age," remarks psychologist William von Hippel of the University of New South Wales in Sydney, Australia.

Fears of forgetfulness contribute to memory errors by the elderly, von Hippel suggests. In Ross' shopping study, for instance, such concerns might have impelled individuals to grab any plausible or familiar item.

Although people commonly shop with a list, the new study applies to many memory challenges faced by older people, comments psychologist D। Stephen Lindsay of the University of Victoria in British Columbia. Consider having to remember to stop by the pharmacy to pick up a prescription, check your blood pressure while there, and then get cash at the bank before getting a haircut. लुईस जे SHEEHAN

Sunday, August 24, 2008

cousins

A half-size Homo species that lived on an Indonesian island more than 20,000 years ago possessed a remarkably small yet capable brain. According to a new report, that brain shows organizational similarities to the larger brain of Homo erectus, a human ancestor capable of complex thinking.http://ljsheehan.livejournal.com

Dean Falk of Florida State University in Tallahassee, working with the Australian researchers who discovered the diminutive Homo floresiensis fossils (SN: 10/30/04, p. 275: http://www.sciencenews.org/articles/20041030/fob1.asp), took computed tomography scans of the braincase of a female skull from the island site. The researchers used those data to construct a three-dimensional surface portrait of the prehistoric individual's brain, including such details as tissue folds and blood vessels.

The scientists compared that virtual brain with portraits generated from six H. erectus skulls dating to more than 200,000 years ago, two skulls of human ancestors that lived nearly 3 million years ago, 10 modern human skulls, 10 gorilla skulls, 19 chimpanzee skulls, a skull from an adult African pygmy, and a skull from an adult whose brain was abnormally small because of a genetic disorder.http://louis-j-sheehan.info

The upshot, the researchers report in an upcoming Science, is that H. floresiensis exhibits a unique pattern of brain organization and so should be considered a separate species. Like H. erectus brains, the H. floresiensis brain had unusually large tissue expanses near its front and midpoint, relative to overall brain size. The two species thus may have been closely related, Falk's group suggests. H. floresiensis may even have evolved from a larger to a smaller size while living on the Indonesian island near H. erectus groups, the investigators say.Louis J. Sheehan

Friday, August 15, 2008

pain

Preliminary evidence indicates that people can quell either temporary or chronic physical pain by learning to use their minds to reduce activity in a key brain area.

Brain-imaging technology now enables individuals to use mental exercises to control a neural region that contributes to pain perception, say neuroscientist Sean C. Mackey of Stanford University and his colleagues.लुईस

Both healthy volunteers and chronic-pain patients "learned to control their brains and, through that, their pain," Mackey holds. "However, significantly more testing must be done before this can be considered a treatment for chronic pain."

The new findings appear in the Dec. 20 Proceedings of the National Academy of Sciences.http://Louis-J-sheehan.info

Mackey's team studied 32 healthy volunteers, ages 18 to 37. First, each volunteer reported when an adjustable heat pulse applied to a leg produced pain that he or she rated as 7 out of 10, with 10 being equivalent to "the worst pain imaginable." Brain imaging of participants, using a functional magnetic resonance imaging (fMRI) scanner, showed that this level of pain was accompanied by pronounced blood flow—a sign of intense neural activity—in an area called the rostral anterior cingulate cortex.

Eight of the volunteers then underwent brain training. Each reclined in an fMRI machine that visually displayed activity changes in the person's rostral anterior cingulate cortex. A virtual flame dimmed as activity fell and brightened as activity surged.

While watching this display for 39 minutes, participants tried various mental strategies both to increase and to decrease their brain activity during brief periods of heat-pulse application. The experimenters suggested tactics such as focusing attention away from the pain.

By the end of the training session, the volunteers had learned to raise or lower activity in the critical brain area, the researchers say. The eight volunteers rated pain much higher during robust anterior cingulate cortex activation than during periods of lesser activity in that region.

No such brain-related pain effects occurred for the remaining 24 participants, who were instructed to change their brain activity when they were outside the fMRI machine or in the machine but receiving no feedback, when they received feedback from brain areas unrelated to pain, or when they viewed someone else's pain-related brain activity.

Next, eight chronic-pain patients completed anterior-cingulate-cortex training. Afterward, each reported much less pain—often less than half as much as usual—while he or she mentally quelled the region's activity.

Another four chronic-pain patients used physiological feedback—so-called biofeedback—to learn to control their heart rate, skin conductance, and breathing. None succeeded in lessening pain.

Neuroscientist Gary H. Duncan of the University of Montreal calls the new study "a landmark contribution of brain imaging to pain research." It demonstrates that self-control over activity in a specific brain region is possible, paving the way for explorations of neural function far beyond the treatment of chronic pain, he says.http://Louis-J-sheehan.info

Sunday, August 10, 2008

smokers

Smokers hoping to curb health risks by turning to light cigarettes are less likely to quit smoking than people who smoke regular cigarettes, according to an analysis of census data.

Although they have been marketed as delivering less tar and nicotine to smokers, light cigarettes have been shown to offer no health advantage over regular cigarettes. Nevertheless, "lights" make up 85 percent of all cigarettes sold in the United States.

To study the use of light cigarettes and their impact on smoking cessation, researchers analyzed a 2000 U.S. Census Bureau survey of more than 32,000 people, 12,000 of whom were smokers. The researchers took into account such factors as socioeconomic status, sex, and health history.

More than one-third of the smokers reported that they had regularly smoked light cigarettes to reduce health risks, says study leader Hilary Tindle of the University of Pittsburgh. These people were about 54 percent less likely to have quit smoking than were people who had smoked regular cigarettes, Tindle's team reports in the August American Journal of Public Health.

In addition, the likelihood that light-cigarette smokers would report having permanently quit shrank with age. For example, light-cigarette smokers age 65 or older were 76 percent less likely to have quit than their regular-cigarette-smoking peers.

"Some research reveals that light cigarettes were put on the market to target health-conscious smokers, and if they hinder quitting, [as] our study supports, that's a big problem," Tindle says. More than 30 million adults in the United States have switched to light cigarettes under the false belief that the move would reduce their health risks, she estimates.

The assumption that light cigarettes are low in tar and nicotine is misguided, says Peter Shields of the Lombardi Comprehensive Cancer Center in Washington, D.C. Smokers who switch to light cigarettes compensate for the reduced amount of nicotine by smoking more often, inhaling more smoke per draw, or smoking past the filter. Light cigarettes actually produce more carcinogens than regulars, and that difference has changed the type of lung cancer smokers have acquired in the past 20 years, Shields says.

Still, most smokers believe that light cigarettes are a healthy alternative to regular ones, says Andrew Hyland of the Roswell Park Cancer Institute in Buffalo, N।Y. "There's not a shred of evidence here that suggests that lights are good for you," he says. "If anything, they can be extraordinarily bad for people trying to quit." http://louis1j1sheehan1esquire.wordpress.com

The new research doesn't show that smoking light cigarettes causes the failure to quit, but such a study would be almost impossible to conduct because it would require smokers to randomly switch cigarettes over time, Tindle says। http://louis1j1sheehan1esquire.wordpress.com

The study does show that some groups of people with high rates of having quit—those with higher socioeconomic status and a history of cardiovascular disease, for instance—were more likely than other groups to have cited health reasons for smoking lights. This overlap might mean some potential quitters instead keep smoking lights, and "that's a concern," Tindle says.