Pathological liars, cheaters and manipulators aren't like the rest of us. In fact, their brains have unique features that may make it easier for them to deceive others, U.S. researchers say.
Using sophisticated MRI scanning equipment, University of Southern California researchers discovered that habitual liars have 22 per cent more "white matter" and 14 per cent less "grey matter" in the prefrontal region of the brain, compared to normal people.
The white matter is essentially the "wiring," while the grey matter represents the closely packed nerve cells of the brain.
Previous research has shown that the prefrontal cortex plays a key role in people's ability to feel remorse and learn moral behaviour.
So, a "structural difference" in this part of the brain may provide liars with "the tools necessary to master the complex art of deceit," according to the study, published in the British Journal of Psychiatry.
"Lying takes a lot of effort," said one of researchers, Adrian Raine, in a statement released with study. "It's almost mind-reading. You have to be able to understand the mindset of the other person. You also have to suppress your emotions or regulate them because you don't want to appear nervous."
He added that the extra white matter provides the brain with increased "networking" to produce superior verbal and other manipulative skills.
At the same time, the deficit in grey "thinking" matter means fewer moral constraints.
"They have got the equipment to lie and the don't have the 'disinhibition' that the rest of us have in telling the big whopper," Dr. Raine added.
Although a lot more research needs to be done, the findings could eventually have far-reaching effects, said researcher Yaling Yang. Brain scans might help police determine whether a crime suspect is a habitual liar.
And employers might want to use them on people applying for work.
AIDS weakening?
Is the deadly AIDS virus losing some of its punch? Belgian researchers compared HIV samples collected over two periods -- 1986-1989 and 2002-2003 -- and discovered that the newer strains appeared not to multiply as well and were more sensitive to anti-AIDS drugs.
One of the researchers, Eric Artz, told BBC News that the results are "very preliminary," involving just 12 samples from each period. "But we did find a pretty striking observation in that the viruses from the 2000s are much weaker than the viruses from the eighties."
The researchers speculate that the virus could be losing some of its "pathogenic effects" as it passes from one person to next.
The virus, in effect, gets beaten down fighting each person's immune system.
But the study, published in the journal AIDS, seems to fly in the face of recent outbreaks of more virulent stains -- notably one in New York.
Whatever is happening, AIDS is still a life-threatening disease and experts agree that precautions, such as using a condom in sexual relations, must continue to be taken to prevent new infections.
Drug warning
A medication used to treat attention-deficit/hyperactivity disorder could cause some patients to experience suicidal thoughts, the drug's maker disclosed yesterday.
After holding talks with both Health Canada and the U.S. Food and Drug Administration, Eli Lilly has agreed to put warning labels on its product known by the brand name Strattera.
Patients receiving the prescription drug at Canadian pharmacies will be given a printed warning of the potential risk, said Jirina Vlk, a Health Canada spokesperson.
An analysis of several drug trials involving children and adolescents revealed that a small number of them -- five out of 1,357 -- had suicidal thoughts while taking the medication. None of the 851 patients receiving placebos experienced similar thoughts.
Strattera was launched on the Canadian marketplace in March.
A statement, released by the company, says some patients may feel "worse instead of better," particularly within the first few weeks of treatment or when doses are adjusted.
"They may experience unusual feelings of aggression, hostility or anxiety, or have impulsive or disturbing thoughts that could involve self harm."
Patients experiencing these symptoms should see their doctors immediately, but should not stop taking the drug on their own, the company says.
Aging cheek bones
Deep wrinkles, weathered skin and sagging jowls are not the only things that can make your face look haggard and aged. The bones in your face can also "shrink," contributing to an older appearance.
As people age, "facial bones remodel themselves, dissolving, shrinking and leaving empty spaces," David Kahn told a conference of the American Society of Plastic Surgeons and Plastic Surgery in Chicago this week.
As a result, the skin cannot tighten around the bones the way it once did, causing the skin to droop or some facial features to become more pronounced.
Dr. Kahn, a surgeon in Palo Alto, Calif., recently completed a study using CT scans to examine the facial bones of women and men of various ages.
The study revealed that women had a "significant decrease in facial bone volume at a younger age than men," which could cause them to see the signs of aging earlier.
These differences may be one reason why women tend to seek facial cosmetic surgery at a younger age than men, the California surgeon said.