Looks familiar?

Ever had that strange feeling that the face looking back at you in the mirror isn't entirely you? Well, it isn't

New research from Royal Holloway University of London indicates that our perception of our own faces changes according to whom we've been spending time with. We think that we look like them if we've shared an experience with them.

Researchers demonstrated this by asking study participants to look at someone else having their face stroked, while simultaneously having their own features touched. Afterwards, when asked to identify pictures that looked most like themselves, the subjects chose ones that had been subtly changed to look more like the person they had been looking at.

“This means that as a result of shared experiences, we tend to perceive other people as being more similar to us,” says Dr Manos Tsakiris, from the university's psychology department. This holds fascinating implications for how we respond to people from other genders and cultures. The more activities we share with them, the more likely we are to feel and look like them. “If I feel that you are more like me, I might then behave to you in a different way,” says Dr Tsakiris.

But though our perception of faces is flexible, separate research this week shows that our ability to make facial expressions is in-bullt from birth. We don't learn them from our mothers, as once thought.

The study, from San Francisco State University, proved the point by comparing films of the facial expressions of sighted athletes with those who had been blind from birth. Correlating different kinds of smile, frown, and grimace between the two groups in identical social and competitive situations, they found virtually no difference at all - suggesting a genetic source to facial expression.

The researchers believe there could be evolutionary explanations for this: for example, human beings developed an in-built frowning system to keep their mouths shut and to prevent biting when they experienced negative feelings.

Out of control

If your new year resolutions are on the rocks and you can't control yourself from sneaking a fag or bingeing on junk, blame your brain. A new imaging study shows that when a cigarette quitter sees someone else smoking, there's a huge explosion of activity in the part of the brain that controls our impulses, effectively over-riding it.

That's why, the researchers from Duke University conclude, seeing others smoke is the most hazardous hurdle for quitters.

Separate research from Columbia University indicates that women with bulimia have a fault in the brain circuits that control impulsive behaviour. This may explain why they are less able to control their eating urges than the rest of the population.

Sensing danger

A tiny implantable sensor could spell the end of inflatable cuffs and clumsy wearable meters for measuring blood pressure.

Just one millimetre in diameter, the chip is implanted into the femoral artery at the top of the leg where it takes a reading 30 times a second, sending it to an external reading device that patients can wear like a mobile phone on their belt. This can alert doctors if the reading becomes too high.

The developers, from the Fraunhofer Institute for Microelectrical Circuits in Germany, are performing first clinical trials. They believe the innovation will be of particular benefit to people whose blood pressure fluctuates widely, and who currently have to wear cumbersome meters and wires to keep track of it over long periods.

Food for thought

Exercise as much as you can to keep healthy, but if you want to lose weight look at what you eat instead.

The case that diet is more influential than exercise in weight loss has been demonstrated by Loyola University researchers, who compared African-American women in Chicago to women in Nigeria. The Nigerian women were significantly lighter but an analysis found that physical activity in both groups was almost exactly the same. What differed was their diets - 40 per cent fat in Chicago, but mainly roughage and carbs in Nigeria.

“Decreased physical activity may not be the primary driver of the obesity epidemic,” the study says.

Cell division

The prospect of a “magic bullet” treatment for cancer comes from scientists who have found a new way to differentiate between cancer cells and normal cells masquerading as cancer cells.

Research into cancer has been impeded by the fact that normal stem cells and cancerous stem cells can look alike. This means that tests comparing the way both

types of cells work are often thwarted. But the discovery by cancer experts at McMaster University, Canada, of a new way of picking apart the cells means the exact effect of treatments can be accurately gauged on cancerous and normal cells. “We can use this to find a drug that kills cancer cells first and spares the normal healthy cells,” says the scientific director, Mike Bhatia.

Mind your language

Diary date for those foul of mouth: in June, Lancaster University is hosting the 2009 International Conference of the Linguistic Politeness Research Group. Its theme is “communication that might be described as impolite, rude, aggressive or face-attacking”.

Also of interest will be a paper in the Australian Law Journal entitled Cost/Benefit Analysis of Judges Being Offensive to Each Other. It recommends that judges moderate their insults about other judges when overturning judgments. This is Australia