Is hypnosis real, and can it be used to help people fight addictions or lose weight?
—Suzanne Napier, Claremore, Okla.
Psychologists Grant Benham of the University of Texas–Pan American and Michael R. Nash of the University of Tennessee, Knoxville, reply:
HYPNOSIS IS REAL, but many popular ideas about it are not. When used responsibly by medical professionals as one element in a broader treatment plan, hypnosis can help patients afflicted with various emotional and medical problems.
Hypnosis is a product of sustained, focused attention coupled with suggestions for alterations in subjective experience, perception, emotion, thought or behavior. The degree to which a hypnotized person experiences these alterations depends on his or her natural ability to experience hypnosis rather than on the “power” of the hypnotist or any particular technique. This innate ability does not change much over time: certain people are simply more susceptible to hypnosis than others are.
How hypnosis works is an enduring focus of scientific inquiry. Evidence indicates that hypnotic suggestions can modify the way the brain processes information, thereby affecting perception. If a person hears a hypnotic suggestion that he or she will not feel pain, certain areas of the brain may still register that the body is receiving a painful stimulus, but the brain’s normal “emotional” reaction is less than it would be otherwise.
Hypnosis can help some patients who suffer from pain or debilitating anxiety or who wish to curb addictions or lose weight. But hypnosis is almost never a stand-alone treatment, nor is it a foolproof way to cure a person of unhealthy habits. These and other sensationalist claims fail the test of science. For instance, a hypnotized person is not under the control of the hypnotist, and individuals usually remember everything that occurred during hypnosis. Furthermore, memories of past events are not infallibly true.
Why does the outer surface of the brain have folds?
—Tom Laudate, Brighton, Mass.
Neuroscientists Claus C. Hilgetag of Jacobs University Bremen in Germany and Helen Barbas of Boston University explain:
perception, emotion, thought and all other forms of conscious experience arise from the cerebral cortex, the outermost layer of the brain. As animals evolved to use more of these high-level processes, they eventually needed more space for this layer of gray matter than the inside surface of the skull could provide. Folds maximize the surface area available for the cerebral cortex without increasing the size of the head.
Dogs, cats, apes, dolphins and humans have folded brains, whereas animals with smaller brains do not. The tissue sheet of the human cerebral cortex is about three times as large as the inside surface of the skull. Its folding pattern is far from random, however—very unlike a crumpled sheet of paper. In the 19th century scientists proposed that simple mechanical principles might underlie the brain’s characteristic structure. They also postulated that the brain’s surface shape (morphology) and function were related. For decades, these ideas seemed naive next to emerging genetic theories. Recent studies, however, have given new support to the concept that mechanical factors play a key role in brain morphology and function.
Nerve fiber bundles are tense, like stretched elastic. Regions in the brain that are densely connected are pulled toward one another, producing outward bulges between them—the hills of the cortical landscape. Weakly connected regions drift apart, forming cortical valleys. The stretching and compression of brain tissue also have an effect on the architecture of the cortex and the shape of individual cells, most likely affecting brain function.
One example that illustrates this principle is the asymmetry between the language regions in the left and right hemispheres. A massive fiber bundle connects frontal and posterior language regions in each hemisphere, but the bundle is denser and therefore pulls harder on the left—complementing the idea that in most people the left hemisphere is dominant in language processing. Observations of this type have led scientists to return to the ideas first proposed by anatomists in the 19th century. Modern techniques have shown that the landscape of the brain correlates with brain function after all.
Have a question? Send it to editors@sciammind.com
—Suzanne Napier, Claremore, Okla.
Psychologists Grant Benham of the University of Texas–Pan American and Michael R. Nash of the University of Tennessee, Knoxville, reply:
HYPNOSIS IS REAL, but many popular ideas about it are not. When used responsibly by medical professionals as one element in a broader treatment plan, hypnosis can help patients afflicted with various emotional and medical problems.
Hypnosis is a product of sustained, focused attention coupled with suggestions for alterations in subjective experience, perception, emotion, thought or behavior. The degree to which a hypnotized person experiences these alterations depends on his or her natural ability to experience hypnosis rather than on the “power” of the hypnotist or any particular technique. This innate ability does not change much over time: certain people are simply more susceptible to hypnosis than others are.
How hypnosis works is an enduring focus of scientific inquiry. Evidence indicates that hypnotic suggestions can modify the way the brain processes information, thereby affecting perception. If a person hears a hypnotic suggestion that he or she will not feel pain, certain areas of the brain may still register that the body is receiving a painful stimulus, but the brain’s normal “emotional” reaction is less than it would be otherwise.
Hypnosis can help some patients who suffer from pain or debilitating anxiety or who wish to curb addictions or lose weight. But hypnosis is almost never a stand-alone treatment, nor is it a foolproof way to cure a person of unhealthy habits. These and other sensationalist claims fail the test of science. For instance, a hypnotized person is not under the control of the hypnotist, and individuals usually remember everything that occurred during hypnosis. Furthermore, memories of past events are not infallibly true.
Why does the outer surface of the brain have folds?
—Tom Laudate, Brighton, Mass.
Neuroscientists Claus C. Hilgetag of Jacobs University Bremen in Germany and Helen Barbas of Boston University explain:
perception, emotion, thought and all other forms of conscious experience arise from the cerebral cortex, the outermost layer of the brain. As animals evolved to use more of these high-level processes, they eventually needed more space for this layer of gray matter than the inside surface of the skull could provide. Folds maximize the surface area available for the cerebral cortex without increasing the size of the head.
Dogs, cats, apes, dolphins and humans have folded brains, whereas animals with smaller brains do not. The tissue sheet of the human cerebral cortex is about three times as large as the inside surface of the skull. Its folding pattern is far from random, however—very unlike a crumpled sheet of paper. In the 19th century scientists proposed that simple mechanical principles might underlie the brain’s characteristic structure. They also postulated that the brain’s surface shape (morphology) and function were related. For decades, these ideas seemed naive next to emerging genetic theories. Recent studies, however, have given new support to the concept that mechanical factors play a key role in brain morphology and function.
Nerve fiber bundles are tense, like stretched elastic. Regions in the brain that are densely connected are pulled toward one another, producing outward bulges between them—the hills of the cortical landscape. Weakly connected regions drift apart, forming cortical valleys. The stretching and compression of brain tissue also have an effect on the architecture of the cortex and the shape of individual cells, most likely affecting brain function.
One example that illustrates this principle is the asymmetry between the language regions in the left and right hemispheres. A massive fiber bundle connects frontal and posterior language regions in each hemisphere, but the bundle is denser and therefore pulls harder on the left—complementing the idea that in most people the left hemisphere is dominant in language processing. Observations of this type have led scientists to return to the ideas first proposed by anatomists in the 19th century. Modern techniques have shown that the landscape of the brain correlates with brain function after all.
Have a question? Send it to editors@sciammind.com
