Tag Archives: Cognitive Neuroscience

Left Hand Reaches Brain First

When patients had both hands transplanted, their brains re-established connections much more quickly with the left hand than the right,  a team of researchers in France reports. W
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The sample was small, just two patients, but both had been right-handed before losing their hands, and both followed a pattern of reconnection with their brain that was quicker for the left hand.

The study, led by Angela Sirigu of the Center for Cognitive Neuroscience at the University of Lyon, France, is reported in Tuesday’s edition of Proceedings of the National Academy of Science.

The research shows that even years after loss of hands the brain can reorganize and rewire itself to recognize and connect to a replacement.

It also came just days after French physicians, in a 30-hour operation, performed the world’s first simultaneous partial-face and double-hand transplant. Paris’ Public Hospital authority described the recipient as a 30-year-old burn victim who was injured in a 2004 accident.

Sirigu’s team used magnetic imaging to study the brains of people who lad lost both hands and to see how the motor region that controls movement responded after new hands were transplanted.

The first case involved LB, a 20-year-old man injured in 2000, who received the transplants in 2003 after having used artificial hand devices in the meantime.

He was checked periodically and the researchers found his brain re-established nerve connections to control the left hand by 10 months, while it took 26 months to complete the rewiring needed for the right hand.

“Interestingly, despite that LB was right-handed, and that after his amputation he used his prosthetic device mostly with his right hand,, hand preference shifted from right to left after he had the graft,” the researchers reported.

The second patient studied, CD, was a 46-year-old man who lost both hands in 1996 and received a dual hand transplant in 2000. He was tested by the researchers in 2004, 51 months after the transplant. Strong connections in the brain were observed for the left hand, but not yet the right.

The researchers said more study is needed to determine the reason that the brain reconnected more efficiently to the left hand in these patients. Possibilities include a basically better connection to the left hand, factors in the way that the brain reorganizes itself during the process of the loss of a hand and its later replacement, or perhaps some pre-existing difference in brain organization.

In general, experiments have shown that the right side of the brain controls the left side of the body and many researchers believe it also dominates in such areas as spatial abilities, face recognition, visual imagery and music. The left side of the brain controls the right side of the body and is thought to dominate in language, math and logic. However, many traits are shared by both sides, and if one side is damaged the other can take over many of its functions.

The research was supported by the U.S. National Science Foundation, the French National Center for Scientific Research, the International Brain Organization and other organizations in Brazil, France and Canada.

Sources: The Times Of India

Train That Brain

The negative effect of poverty on the intellectual level of children can be reversed.

It may be a politically incorrect question to ask, but the answer may have profound implications for socio-economic development. How well can children from poor or uneducated families do in life? One could make the question even more incorrect, but at the least, equally relevant: what is the influence of children’s family backgrounds on their subsequent mental development? Research in the last few years has provided partial answers to the question, and they are deeply disturbing.

It now turns out that a child’s brain develops according to the stimulus it receives at home.
If you do not provide complex inputs, you do not get complex brains.

To give one example, the more sophisticated the language used at home, the better the chances of good brain development in the first 10 years of a child’s life.

To put it bluntly, if the parents are uneducated, the children can often end up with deficient brains by the age of 10, compared with children from more educated families. Is this the reason why poverty runs in many families through generations?

Scientists from the University of California, Berkeley, are conducting a set of experiments to understand the real nature of the problem. They put cameras in the dining rooms of families — rich and poor — to monitor dinner time conversation. They got children to their labs and tried to give them tasks and measure the brain response. Their initial finding: the brains of children from poor families often resemble that of stroke victims by the age of 10.

Research in other labs around the world corroborates this finding, while also providing explanations as well as solutions to the problem. Parents in poor families do not talk much to their children. “We hope that parents in poor families will at least talk to their children more than they do,” says Mark Kishiyama, psychologist at the University of California, Berkeley. But even if they do, their language is not complex enough. In fact, Adele Diamond, professor of psychiatry at the University of British Columbia, has shown that children in poor families hear 30 million fewer words by the time they are four years old.

Those with low socio-economic status perform poorly in language tests and long-term memory tests. Martha Farah, director at the Centre for Cognitive Neuroscience at the University of Pennsylvania, showed such differences two years ago. Enrico Mezzacappa at the Children’s Hospital in Boston also showed three years ago that low income children perform poorly in speed and accuracy in some problems when compared with those from higher income families. While common sense can attribute these differences to a lack of education and opportunities, neuroscientists suspected that some of these disparities stemmed from differences in the brain. There is now substantial proof for the differences of brain development in children.

The problem is in an area of the brain called the prefrontal cortex. This area is in the front part of the brain, just behind the forehead. The prefrontal cortex is the seat of problem solving and creativity. A deficient prefrontal cortex makes you poor at complex tasks and problem solving. The experiment now being conducted at the University of California at Berkeley has already shown that poor children have deficient prefrontal cortex, thus substantiating the research of Martha Farah. But we also know the reasons, and other research provides us with a means of solving the problem.

It is not just the lack of intellectual stimulus that interferes with brain development. Poor children are usually under high stress, and it is known that high stress interferes with brain development, by producing chemicals that destroy neurons. Another important factor is pollution: they are exposed to a higher amount of pollutants — lead in water is an example — than children in richer families. All these factors combine to work against the brains of poor children. No wonder, then, that poor children are often not able to measure up to their richer counterparts if they manage to enter institutions of higher learning.

However, science also provides us with a solution to the problem.
“The differences in the brain of children can be reversed with proper training,” says Tom Boyce, a developmental psychobiologist at the University of British Columbia. Neuroscientists are now discovering that the brain remains plastic well into old age. For example, in experiments performed at the University of California, San Francisco, scientists have taken old rats — with only a few weeks to live — and made their brains look young purely by providing more inputs.

There is now a booming industry in the West called the brain improvement industry. Some of their products provide mental exercises with visual and auditory inputs that can improve the brain even in old age. We can thus train young brains to be on a par with those of children from more privileged backgrounds, provided we recognise the problem first.

Sources: The Telegraph (Kolkata, India)

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