Too much thinking may not be good

While introspection is a good thing, but too much "thinking about your thinking" might not be as beneficial as you thought.

A new study found that in people who are good at turning their thoughts inward and reflecting upon their decisions, the size of a specific region of the brain is larger than those who do not.

This act of introspection-or "thinking about your thinking" - is a key aspect of human consciousness, though scientists have noted plenty of variation in peoples' abilities to introspect.

Based on the findings, the researchers, led by Prof. Geraint Rees from University College London, suggests that the volume of gray matter in the anterior prefrontal cortex of the brain, which lies right behind our eyes, is a strong indicator of a person's introspective ability.

However, the researchers found that some people think too much about life.

These people have poorer memories, and they may also be depressed.

In addition, they say the structure of white matter connected to this area is also linked to this process of introspection.

It remains unclear, however, how this relationship between introspection and the two different types of brain matter really works.

The findings establish a correlation between the structure of gray and white matter in the prefrontal cortex and the various levels of introspection that individuals may experience.

In the future, the discovery may help scientists understand how certain brain injuries affect an individual's ability to reflect upon their own thoughts and actions.

With such an understanding, it may eventually be possible to tailor appropriate treatments to patients, such as stroke victims or those with serious brain trauma, who may not even understand their own conditions.

"Take the example of two patients with mental illness - one who is aware of their illness and one who is not. The first person is likely to take their medication, but the second is less likely.

"If we understand self-awareness at the neurological level, then perhaps we can also adapt treatments and develop training strategies for these patients," said one of the study's authors, Stephen Fleming from University College London.

"We want to know why we are aware of some mental processes while others proceed in the absence of consciousness.

There may be different levels of consciousness, ranging from simply having an experience, to reflecting upon that experience.

Introspection is on the higher end of this spectrum-by measuring this process and relating it to the brain we hope to gain insight into the biology of conscious thought," said Fleming.

(ANI)

Touching own injury 'cuts pain'

Touching is an important way of sending a picture of our body to our brain. There may be a very good reason why people clutch a painful area of their body after receiving an injury, according to a study.

Touching the affected area allows a picture of the body to form in the brain, says a study in Current Biology.

Researchers at University College London (UCL) found that the way the body is represented in the brain is key to reducing perceptions of acute pain.

But it does not work if someone else touches the injury, they say.

Scientists from the Institute of Cognitive Neuroscience at the UCL studied the effects of self-touch in people who were made to feel pain using an experimental model called the Thermal Grill Illusion (TGI).

Healthy volunteers were asked to put their index and ring fingers in warm water and their middle finger in cold water.

This generates a feeling that the middle finger is painfully hot, explains the study.

Pain relief

Lead researcher Dr. Marjolein Kammers said: "The brain doesn't know this is an illusion of pain but it does allow scientists to investigate the experience of pain without causing injury to anyone." The pain experienced by the middle finger reduced most - by 64% - when TGI was induced in an individual's two hands and then all three fingers on one hand touched the same fingers on the other hand.

The same level of pain relief was not evident when only one or two fingers were pressed against each other or when someone else's hand was pressed against the affected hand.

Professor Patrick Haggard, also from UCL, explained: "We showed that levels of acute pain depend not just on the signals sent to the brain, but also on how the brain integrates these signals into a coherent representation of the body as a whole.

"Self-touch provides strong evidence to the brain about the correlation of sensory information coming from different parts of the body.

"This helps to give us the experience of our body as a coherent whole," he said.

Dr Kammers is currently researching whether the pain-relieving effect of touching fingers and hands together can be replicated in other parts of the body.

Previous studies of chronic pain, following the amputation of a limb for example, have shown the importance of the way the body is represented in the brain when pain is experienced. Thanks to this study, researchers say they now have an experimental model to study how the brain's sense of the body influences acute pain.

- BBC

Scientists hail one-off test for prostate cancer

A single blood test for prostate cancer in middle-aged men can predict those at highest risk of dying from the disease, a study has shown.

Researchers have found that 90 per cent of prostate cancer deaths occurred in men with above-average levels of prostate specific antigen (PSA) in their blood at age 60.

The finding, published in the British Medical Journal, casts the controversy over PSA screening in a new light. Although regular screening is widespread in the US, the PSA test is unreliable and has been blamed for causing an epidemic of over-treatment. The problem is that many prostate cancers are slow growing and cause little harm.

But the PSA test cannot distinguish the harmless cancers from the aggressive ones. It is estimated that up to 40 per cent of men aged 70 have prostate cancer but few are aware of it and most will die of something else. The latest study of Swedish men by US researchers suggests that a one-off test at age 60 can identify the half of the male population that is at negligible risk of dying from prostate cancer. Screening could then be concentrated on the other half, which would be likely to improve the benefits and reduce the risks of over-diagnosis and over-treatment.

However, the men who have a greater than negligible probability of developing the disease need not despair. A raised PSA level "is far from being an inevitable harbinger of advanced prostate cancer," the researchers said. Even in those among the top 5 per cent of PSA level reading, only one in six will die of the cancer by the age of 85.

Prostate cancer is the most common cancer in men, with 35,000 new cases a year and 10,000 deaths. It is also one of the most rapidly increasing cancers and there is an urgent need for a reliable test.

In an editorial published with the paper in the BMJ, Gerald Andriole, chief of urologic surgery at Washington University School of Medicine, wrote that young men at high risk of prostate cancer, such as those with a strong family history and high PSA level, should be followed closely, while elderly men and those with a low risk of the disease could be tested less often, if at all.

"Approaches such as these will hopefully make the next 20 years of PSA-based screening better than the first 20," he wrote.

Courtesy:

The Independent

Evolution of malaria traced back to greatest ape

by Steve Connor

The malaria parasite, which has killed more people than any other infectious disease in history, almost certainly originated in gorillas infected by a genetically identical microbe, scientists have discovered.

An exhaustive study of nearly 3,000 biological specimens from wild apes living in 57 field sites across central Africa has pinpointed the western lowland gorilla of the Congo as the most likely source of Plasmodium falciparum, the most deadly malaria parasite in humans.

The findings overturn earlier suggestions based on a more limited study that wild chimpanzees were the original reservoir of the human disease, a theory that can now be discounted, the scientists said.

Western lowland gorilla

They suggest that the malaria parasite crossed the "species barrier" from gorillas to humans only once as a result of a mosquito bite, causing the global epidemics that have ravaged successive generations of people throughout history.

The researchers believe identifying the original source of the most dangerous form of malaria will lead to greater knowledge of how to combat its spread and how to improve its treatment.

"Understanding where a human pathogen like Plasmodium falciparum originated can be an important step in learning how to prevent and treat the disease that it causes," said Beatrice Hahn of the University of Alabama in Birmingham, US, who led the research team.

"Like AIDS, malaria is of primate origin. Studies of the primate precursors of HIV have unravelled many aspects of Aids. I expect the same to happen when the biology of the gorilla precursor of P. falciparum is compared to that of its human counterpart," Dr. Hahn said.

Malaria, which is caused by a microscopic blood parasite transmitted by mosquitoes, infects about 500 million people a year, killing about 2 million. It was known by the ancient Chinese, and has been the scourge of western civilisations, from the ancient Egyptians to the British Empire.

Julian Rayner of the Wellcome Trust Sanger Institute in Cambridge, where the genetic sequencing of the malaria parasites from the ape samples was carried out, said it was not possible from the findings to determine exactly when the cross-infection from gorillas to humans took place.

"At some time it seems to have jumped the barrier from gorillas into humans but when this happened is difficult to know.

One theory is that it was about 12,000 years ago, or even earlier," Dr Rayner said.

"Another unanswered question is whether this jumping of the species barrier is still happening. The current data suggests it happened just once, but we don't really know." The study, which was published in the journal Nature, was based on an analysis of 2,700 samples of ape faeces using a novel technique that could identify and sequence the DNA of P. falciparum parasites in the animals.

The results indicated the western lowland gorilla has carried an ancient parasite that is almost certainly the immediate ancestor of P. falciparum, causing the most deadly form of malaria in humans.

The phylogenetic tree the scientists compiled indicated a single leap from gorilla to man, said Martine Peeters of the University of Montpellier, France.

"The notion that P. falciparum could have been transmitted only once from gorillas to humans spawning what we now recognise as a global epidemic is remarkable.

However, we cannot exclude the possibility that transmissions between gorillas and humans occur at a local level but have not spread further around the world," Dr Peeters said.

It is unlikely that gorillas infected with the Plasmodium parasite suffer badly from malaria because infection levels are so high, Dr Rayner said.

There is another form of malaria infecting apes in Indonesia that can be transmitted to humans by mosquito bites, he said.

- The Independent UK

Blood test to predict susceptibility to heart disease, diabetes

London: Scientists have developed a simple two-pound blood test that has the potential to test a person's chances of developing heart disease and diabetes.

The test would be made available in five years and anyone found to be prone could then take potentially life-saving steps to improve their health.

"This may give us a new way of assessing the health of blood vessels of patients with diabetes and also in the general population," the Daily Mail quoted researcher Manual Mayr as saying.

The test measures levels of a small strand of genetic material called MiR-126, which plays a crucial role in keeping our arteries healthy.

As our blood vessels become damaged, levels of MiR-126 fall.

Scientists from the King's College London have shown that men and women with very low levels are twice as likely to develop heart problems in the following decade as others.

The research is in its infancy and but Mayr said that a basic testing kit that would calculate a person's odds of heart disease or diabetes in the next decade could be in widespread use by 2015.

The blood test would pick up signs of damage in their arteries, allowing them to start on drugs and make changes to their lifestyle.

The kit could also be used to monitor the progress of heart disease, making it easier for cash-strapped doctors to separate those who need the most gruelling treatments from others.

Jeremy Pearson of the British Heart Foundation, which funded the research, said: "This is important because right now there is no quick and easy way to monitor blood vessel health.

"Problems go unnoticed until symptoms appear and the first symptom could be as serious as a heart attack."

- (ANI)