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The Amazing Brain

The brain has many parts: the subcortex, or "old brain," responsible for the most basic functions such as breathing, eating, drinking, and sleeping. The neocortex, or "new brain," is the part of the brain where complex activity takes place. Other parts of the brain include the cerebrum and the corpus callosum. But more interesting than the parts of the brain is how they work, and the research that tells us new things every day. Here are two amazing brain stories.

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Can thinking improve your health?
Have you ever seen the sculpture by Rodin called "The Thinker"? It depicts a man sitting down, leaning his chin on his hand, deep in thought. Well, chances are, if The Thinker had been real, he would have had a strong immune system. Scientists have shown that complex thinking can help boost your immune system. Researchers at the University of California at Berkely performed an experiment that showed an increase in CD4 T cells in women taking part in difficult cognitive tasks. A CD4 T cell is a type of cell called a lymphocyte which is produced by the immune system and helps other cells fight infection. Scientists at Berkeley already knew that the brain could affect the immune system, but they didn't know exactly how. Studies had shown that animals with a damaged dorsolateral frontal cortex (part of the cerebral cortex) had lower T cells than animals with healthy brains. Hence, researchers decided to do a study that would stimulate the dorsolateral frontal cortex in a person to see if the number of T cells rose. The researchers decided to compare the T cells in a group of female bridge players before and after a game. Bridge is an extremely complex card game that involves a lot of intense thought. The scientists found that the women's CD4 T cells were significantly higher after the bridge game than before the game, and that the CD4 T cell levels had not changed at all in a woman who just sat quietly and listened to music during the same game. Of course there are still some mysteries. Scientists don't know how long these elevated T cell levels last; they also don't know if the levels are high enough to actually improve a person's health.

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Does your brain change?
You may have heard stories about people going blind (losing their sight) and finding that their sense of smell, touch, hearing, and taste had become much more sensitive. But did you ever wonder what happened to their sight, or rather, what happened to the part of the brain that controlled sight? Did it disappear? Go to sleep? Dr. Alvaro Pascual-Leone tried to answer these questions when he did a study featured on the PBS (public television) series "Changing Your Mind." Dr. Pascual-Leone wanted to see what happened when a person with vision (named Michelle) was blindfolded for a week. He wanted to see if her brain "rewired" itself to make up for the loss of sight. In other words, he wanted to see what the visual part of the brain did when it was no longer necessary. On the first day with Michelle, before she was blindfolded, Dr. Pascual-Leone took "pictures" of her brain with an MRI while she did a Braille test. (Braille is a way of printing that uses raised dots so that blind people can read with their hands.) Not surprisingly, as she touched the Braille letters, the touch-sensing region of her brain lit up on the MRI, showing that it was active. Then Michele wore a blindfold for a week and lived as if she were blind. She studied Braille intensively and took part in other activity involving her hands, such as drawing and sculpting. She walked using a cane. At the end of the week, Dr. Pascual-Leone looked at Michelle's brain again as she did another Braille test. This time, instead of the touch-sensing region lighting up, Michelle's visual cortex (the part that controls sight) lit up. But why would the visual part of Michelle's brain be active if she was reading with her hands? Dr. Pascual-Leone's theory is that the brain "rewired" itself. When the visual cortex didn't have a job any more, it took over the work of the touch-sensing region. To test his hypothesis even further, he used transcranial magnetic stimulation (TMS—an electrical stimulus) to "confuse" Michelle's visual cortex, and then had her take another Braille test. Michelle noticed that her fingers felt less sensitive, proving Dr. Pascual-Leone's point that the visual cortex controlled her sense of touch. With this experiment, Dr. Pascual-Leone has shown that the brain can totally reorganize itself within the course of a few days. Pretty amazing!

Getting the Main Ideas

Write T on the lines before the statements that are true, according to the reading. Write F on the lines before the statements that are false.


1		Paragraph 1 Scientists have proved that thinking can improve your health. The immune system produces CD4 T cells. Listening to music can improve your immune system. Taking part in difficult cognitive tasks can increase your number of CD4 T cells.


2		Paragraph 2 The visual cortex controls human vision. When a person goes blind, their visual cortex stops working. When Pascual-Leone "confused" Michelle's visual cortex, her sight became worse. Dr. Pascual-Leone showed that the human brain can change in only a couple of days.

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