
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.
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Western lowland gorilla
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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)
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