Present at the Future Read Free Page B

protons in the hydrogen atoms are facing either up toward your head or down toward your feet. The hydrogen atoms’ opposite directions means that most of them cancel out each other’s electrical charge. But a fewremain, and when the machine sends a beam of radio waves to your brain or to the part of your brain that’s being scanned, the pulse makes them resonate and give off radio signals of their own. When the machine shuts off the pulse, the hydrogen atoms return to their normal alignment and release energy, giving off a signal. The machine’s sensors detect these signals and feed them into a computer, which generates an image of the different types of tissue in the brain.
    Magnetic resonance images are good at detecting changes in the brain, which occur every time you learn something new. MRI has been used to help education researchers develop new teaching methods that have proven to help elementary-school children—most of them are boys—with dyslexia and other reading difficulties. Magnetic resonance images showed researchers that parts of the brains of struggling readers were different from those of successful readers. In one study at the University of Washington, researchers took magnetic resonance images while struggling readers pronounced certain words while lying in the machine. Then the boys were trained in a special curriculum designed to help them read more easily. At the end of the program, the boys underwent MRI again while they read words aloud. The images showed that their brains now looked more like those of normal readers—proof positive that the innovative reading training that they had been given worked. At Yale University, another research team is taking magnetic resonance images of dyslexic readers throughout their lives, for a long-term study of how the brain changes.
    Magnetic resonance images are often very colorful and beautiful, as well as clear and detailed. MRI is faster than PET, but it still can’t keep up with the extremely rapid changes inside the brain and give us the best possible picture of the brain at work.
    Now a new imaging technology in limited use can record brain activity by the millisecond. Magnetoencephalography, or MEG, is still extremely expensive, so there are only a few of the new machines that the imaging requires in existence. Because your brain—like your entire body—works by electricity, it produces a magnetic field. MEG works by detecting the very faint magnetic fields generated by the tiny electric currents from your neurons that are recorded on EEGs. When you have a MEG scan, you sit under a big, very heavy machine that positions magnetic detection coils bathed in helium over your head. The helium chills the coils to supersensitive, superconducting temperatures. Your brain’s magnetic field induces a current in the coils that in turn induces a magnetic field in an instrument called a superconducting quantum interference device, or SQUID. The magnetic field can be translated into computer-processed images that provide the most accurate monitoring and timing of brain-cell activity. Of all imaging technologies, MEG provides the best information, so let’s hope that it will become cheaper and more available in the future.
    Besides imaging, we’re learning a lot about the brain from developments in genetics. The Human Genome Project has linked certain genes with normal brain function, such as learning and memory, and with some mental disorders as well. By adolescence, the effects of genes become apparent—including genetically related dysfunctions such as depression or schizophrenia. We know that mental illnesses like these can begin in adolescence, and we can see the changes they cause in the brain in imaging. Pharmaceutical companies have developed new drugs that change brain chemistry in positive ways and help relieve the suffering of people with depression or schizophrenia. But some doctors and philosophers worry that if we know how to explain the brain, we