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Sunday, February 27, 2011

Are brains shrinking to make us smarter?

I know that in the individual level, this is true - the billions of cells and full-connection synapses are all there, and in the growing months and years, there is a necessity for much of the cells and synapses to be cut and broken: to give way to learning and strengthening the connections that retain our learning.

And it is observed in the whole human populace as well.

Read on...

Posted: 06 February 2011

WASHINGTON: Human brains have shrunk over the past 30,000 years, puzzling scientists who argue it is not a sign we are growing dumber but that evolution is making the key motor leaner and more efficient.

The average size of modern humans -- the Homo sapiens -- has decreased about 10 percent during that period -- from 1,500 to 1,359 cubic centimetres, the size of a tennis ball.

Women's brains, which are smaller on average than those of men, have experienced an equivalent drop in size.

These measurements were taken using skulls found in Europe, the Middle East and Asia.

"I'd called that a major downsizing in an evolutionary eye blink," John Hawks of the University of Michigan told Discover magazine.

But other anthropologists note that brain shrinkage is not very surprising since the stronger and larger we are, the more gray matter we need to control this larger mass.

The Neanderthal, a cousin of the modern human who disappeared about 30 millennia ago for still unknown reasons, was far more massive and had a larger brain.

The Cro-Magnons who left cave paintings of large animals in the monumental Lascaux cave over 17,000 years ago were the Homo sapiens with the biggest brain. They were also stronger than their modern descendants.

Psychology professor David Geary of the University of Missouri said these traits were necessary to survive in a hostile environment.

He has studied the evolution of skull sizes 1.9 million to 10,000 years old as our ancestors and cousins lived in an increasingly complex social environment.

Geary and his colleagues used population density as a measure of social complexity, with the hypothesis that the more humans are living closer together, the greater the exchanges between group, the division of labor and the rich and varied interactions between people.

They found that brain size decreased as population density increased.

"As complex societies emerged, the brain became smaller because people did not have to be as smart to stay alive," Geary told AFP.

But the downsizing does not mean modern humans are dumber than their ancestors -- rather, they simply developed different, more sophisticated forms of intelligence, said Brian Hare, an assistant professor of anthropology at Duke University.

He noted that the same phenomenon can be observed in domestic animals compared to their wild counterparts.

So while huskies may have smaller brains than wolves, they are smarter and more sophisticated because they can understand human communicative gestures, behaving similarly to human children.

"Even though the chimps have a larger brain (than the bonobo, the closest extant relative to humans), and even though a wolf has a much larger brain than dogs, dogs are far more sophisticated, intelligent and flexible, so intelligence is not very well linked to brain size," Hare explained.

He said humans have characteristics from both the bonobo and chimpanzee, which is more aggressive and domineering.

"The chimpanzees are violent because they want power, they try to have control and power over others while bonobos are using violence to prevent one for dominating them," Hare continued.

"Humans are both chimps and bobos in their nature and the question is how can we release more bonobo and less chimp.

"I hope bonobos win... it will be better for everyone," he added.


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Are brains shrinking to make us smarter?

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Thursday, February 10, 2011

Dogs can smell bowel cancer

Dogs are still living up to "being man's best friend."

Dogs aid bowel cancer fight
Posted: 01 February 2011

PARIS : Japanese researchers on Monday reported a "lab" breakthrough: a retriever which can scent bowel cancer in breath and stool samples as accurately as hi-tech diagnostic tools.

The findings support hopes for an "electronic nose" one day that can sniff a tumour at its earliest stages, they said.

Researchers led by Hideto Sonoda at Kyushu University in Fukuoka, Japan, used the specially-trained female black labrador to carry out 74 "sniff tests" over a period of several months.

Each of the tests comprised five breath or stool samples, only one of which was cancerous.

The samples came from 48 people with confirmed bowel cancer at various stages of the disease and 258 volunteers with no bowel cancer or who had had cancer in the past.

They complicated the task for the eight-year-old canine detective by adding a few challenges to the samples.

Around half of the non-cancer samples came from people with bowel polyps, which are benign but are also a possible precursor of bowel cancer.

Six per cent of the breath samples, and 10 per cent of the stool samples, came from people with other gut problems, such as inflammatory bowel disease, ulcers, diverticulitis, and appendicitis.

The retriever performed as well as a colonoscopy, a technique in which a fibre-optic tube with a camera on the end is inserted into the rectum to look for suspect areas of the intestine.

It correctly spotted which samples were cancerous and which were not in 33 out of 36 breath tests, equal to 95 per cent accuracy, and in 37 out of 38 stool tests (98 per cent accuracy).

It performed especially well among people with early stage disease, and its skills were not disrupted by samples from people with other types of gut problems.

Previous research has also found that dogs can sniff out bladder, lung, ovarian and breast cancer.

Using dogs as a screening tool is likely to be expensive.

But the success of this experiment backs hopes for developing a sensor that can detect specific compounds, in faecal material or the air, that are linked to cancer.

There is already a non-invasive method for screening for bowel cancer, which looks for telltale traces of blood in a stool sample. But it is only about 10 per cent accurate in detecting early-stage disease.

The dog used in the Japanese experiment was initially trained for water rescue in 2003 and then began training as a cancer detector in 2005.

Every time she correctly distinguished a cancer sample, she was allowed to play with a tennis ball.

- AFP/il

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Dogs aid bowel cancer fight

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Wednesday, February 9, 2011

Self-control must be learned while young

I was thinking that kids should be kids, and should be allowed they freedom while young.

I could be wrong; or that their childhood 'freedom' has a boundary after all...

Kids, take note!

Kids who misbehave face trouble as adults, says study
Posted: 25 January 2011

WASHINGTON: Children who are over-active, cannot concentrate or act impulsively as early as age three tend to become troubled adults unless they learn self-control along the way, said a study on Monday.

An international team of researchers examined young children in New Zealand and Britain and found that the low-scorers on measures of self-control as kids faced more financial, health and substance abuse problems as they aged.

Measures of low self-control in the study of 1,000 New Zealand children included "low frustration tolerance, lacks persistence in reaching goals, difficulty sticking with a task," said the study in the Proceedings of the National Academy of Sciences.

Other indicators were "over-active, acts before thinking, has difficulty waiting turn, restless, not conscientious."

The children who scored lowest on those counts faced a host of problems as adults, "things like breathing problems, gum disease, sexually transmitted disease, inflammation, overweight, and high cholesterol and blood pressure," the study said.

Researchers also saw those children emerge as adults with financial woes, such as credit card debt.

"They also were more likely to be single parents, have a criminal conviction record, and be dependent on alcohol, tobacco, cannabis and harder drugs," said the study.

"These adult outcomes were predictable across the entire spectrum of self-control scores, from low to high," said Duke University psychologist Terrie Moffitt, lead researcher on the study.

The same researchers also looked at a study of 500 pairs of fraternal twins and Britain and tracked the differences between the lower self-control twin and the higher self-control twin as they aged.

"The sibling with lower self-control scores at age five was more likely than their sibling to begin smoking, perform poorly in school and engage in antisocial behaviours at age 12," the study said.

Co-author Avshalom Caspi of Duke University said the findings suggest that an individual's ability to exert self-control has an influence of its own and is independent from the environment in which one is raised.

"This shows that self-control is important by itself, apart from all other factors that siblings share, such as their parents and home life," said Caspi.

The researchers said they found evidence that children who changed their ways and learn to exert more self-control fared better in adulthood than their counterparts, indicating that behaviour changes can show positive results.

"The good news is that self-control can change. People can change," said Alexis Piquero, a professor of criminology at Florida State University who was not a part of the study.

- AFP/de

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Kids who misbehave face trouble as adults, says study

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Sleep makes better memories

Memories take hold better during sleep
Posted: 24 January 2011

PARIS : The best way to not forget a newly learned poem, card trick or algebra equation may be to take a quick nap, scientists surprised by their own findings reported Sunday.

In experiments, researchers in Germany showed that the brain is better during sleep than during wakefulness at resisting attempts to scramble or corrupt a recent memory.

Their study, published in Nature Neuroscience, provides new insights into the hugely complex process by which we store and retrieve deliberately acquired information - learning, in short.

Earlier research showed that fresh memories, stored temporarily in a region of the brain called the hippocampus, do not gel immediately.

It was also known that reactivation of those memories soon after learning plays a crucial role in their transfer to more permanent storage in the brain's "hard drive," the neocortex.

During wakefulness, however, this period of reactivation renders the memories more fragile.

Learning a second poem at this juncture, for example, will likely make it harder to commit the first one to deep memory.

Bjorn Rasch of the University of Lubeck in Germany and three colleagues assumed that the same thing happens when we sleep, and designed an experiment to find out if they were right.

Twenty-four volunteers were asked to memorise 15 pairs of cards showing pictures of animals and everyday objects. While performing the exercise, they were exposed to a slightly unpleasant odour.

Forty minutes later, half the subjects who had stayed awake were asked to learn a second, slightly different pattern of cards.

Just before starting, they were again made to smell the same odour, designed to trigger their memory of the first exercise.

The 12 other subjects, meanwhile, did the second exercise after a brief snooze, during which they were exposed to the odour while in a state called slow-wave sleep.

Both groups were then tested on the original task.

Much to the surprise of the researchers, the sleep group performed significantly better, retaining on average 85 per cent of the patterns, compared to 60 per cent for those who had remained awake.

"Reactivation of memories had completely different effects on the state of wakefulness and sleep," said lead author Susanne Diekelmann, also from the University of Lubeck.

"Based on brain imaging data, we suggest the reason for this unexpected result is that already during the first few minutes of sleep, the transfer from hippocampus to neocortex has been initiated," she said in an email exchange.

After only 40 minutes of shuteye, significant chunks of memory were already "downloaded" and stored where they "could no longer be disrupted by new information that is encoded in the hippocampus," she explained.

Diekelmann said the positive impact of short periods of sleep on memory consolidation could have implications for memory-intensive activities such as language training.

The findings, she said, also point to a strategy for helping victims of post-traumatic stress syndrome, a debilitating condition caused by extreme experiences.

The reactivation techniques "might prove useful in re-processing and un-learning unwanted memories," she said. "And reactivation of newly learned memories during ensuing sleep could then help consolidate the desired therapeutic effects for the long-term."

Diekelmann cautioned that computers are an imperfect metaphor for the way memories are stored in the brain.

"Human memory is absolutely dynamic. Memories are not statically 'archived' in the neocortex but are subject to constant changes by various influences," she said.

Likewise, the act of remembering does not simply entail "reading" the stored data, she added. "Recall is a reconstructive process in which memories can be changed and distorted."

- AFP/sh

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Memories take hold better during sleep

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Better keep away from junk foods!

WHO calls for junk food ban in schools, playgrounds
Posted: 22 January 2011

Students purchase snacks at a vending machine in a school.
GENEVA: Junk food should not be sold in schools and playgrounds, the World Health Organisation said on Friday in a series of recommendations aimed at promoting a healthy diet and cutting child obesity.

However, it fell short of calling for a ban on advertising directed at children for foods high in saturated fats, sugars or salt, opting instead to ask member states to "consider the most effective approach to reduce" such marketing.

The non-binding recommendations will be put to a high-level meeting on the prevention and control of non-communicable diseases during September's General Assembly in New York, WHO officials said.

"Settings where children gather should be free from all forms of marketing of foods high in saturated fats, trans-fatty acids, free sugars or salt," said the UN health agency.

"Such settings include, but are not limited to, nurseries, schools, school grounds and pre-school centres, playgrounds, family and child clinics and paediatric services and during any sporting and cultural activities that are held on these premises," it added .

Some 43 million pre-school children are obese or overweight, according to WHO data.

"Children throughout the world are exposed to marketing of foods high in fat, sugar or salt, which increases the potential of younger generations developing non-communicable diseases during their lives," it said.

Six out of ten deaths every year are due to cardiovascular diseases, cancers, diabetes and chronic lung diseases, the WHO warned, pointing out that a common factor of the four main diseases is poor diet.

- AFP/de

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WHO calls for junk food ban in schools, playgrounds

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