The Flexible Brain
Modern scanning technology has shown that our brains can
adapt to changing circumstances at any age—if we let them.
by Lisa James
Susan Barry’s eyes crossed when she was three months old. When she looked at something with her left eye, her right eye would turn in, and vice versa. But after three childhood surgeries corrected her appearance “I assumed I had fine vision, even though I had a hard time learning how to drive,” says Barry, a professor of biological sciences at Mount Holyoke College in Massachusetts. “Then I got into college and learned I didn’t have stereovision—I took all these 3D tests and didn’t pass them.” Barry had strabismus, a misalignment of the eyes that confuses the brain and causes loss of 3D vision.
What’s worse, “the same day I learned I didn’t have stereovision I learned I could never get it,” says Barry. That’s because the developing brain was thought to be like a vat of drying concrete: The flexibility that allowed a young child’s brain to acquire skills such as stereovision was simply lost by the time a person reached adulthood. Barry would even use herself as an example in passing along that conventional wisdom to her students.
Barry’s perspective changed, literally and figuratively, when she consulted a developmental optometrist, someone who specializes in problems with binocular vision. “She told me, ‘Your eyes don’t point at the same place in space at the same time,’” Barry recalls. Barry started doing vision exercises with aids such as a Brock string, a series of colored beads on a string that taught her eyes how to work in unison.
At age 48, Barry was finally able to perceive 3D images. “The first time you see in stereo is incredible,” says Barry, who has written about her experience in Fixing My Gaze: A Scientist’s Journey into Seeing in Three Dimensions (Basic Books). “You see that the leaves on a tree have layers of depth; before that the tree seemed sort of flat.”
Barry’s eyes remained the same, but her brain had changed. So had her beliefs about the brain’s limitations. Barry had experienced neuroplasticity, the idea that the brain is capable of renewing itself and remaining flexible no matter how old you are.
The brain contains about 100 billion neurons, which carry the electrical charges that make up nerve impulses. They do not touch each other directly. Instead, chemicals called neurotransmitters carry messages across small spaces known as synapses between neurons.
Over the past several decades, sophisticated brain scans such as functional MRI (fMRI) and PET have turned scientific thinking about the brain on its head. “They began to see that different areas of the brain build more synapses,” says Patt Lind-Kyle, leader of workshops in brain/mind exploration and author of Heal Your Mind, Rewire Your Brain (Energy Psychology Press, www.healrewireyourbrain.com). “In the areas that you use, brain cells grow and multiply.” Barry says that such changes are noticeable when scientists scan the brains of people in certain professions; for instance, “a violinist’s brain has changed because the way they use their left hand is different from the way they use their right.”
This flexibility is not always helpful. “The mind is like software and the brain is like hardware. Whatever the mind does, it affects the brain,” Lind-Kyle says. “If your thinking is negative, you’ll have more cells in that particular area.”
Aging can also affect the brain, especially under adverse conditions. “Aging is accelerated by chronic stress,” says Lind-Kyle, who notes that stress chemicals can damage the hippocampus, the part of the brain responsible for learning and memory. Alzheimer’s disease, a major cause of dementia, affects the prefrontal lobe, which lies behind the forehead. “This is the part that really makes us function as human beings,” says Lind-Kyle. “It’s the center of compassion, of empathy.”
If stress and negativity can damage the brain, acting positively can protect it. “The prefrontal area needs a lot of oxygen and a steady food supply,” says Lind-Kyle. “Meditation provides all that.”
Research shows that meditation helps lower blood pressure, reduce anxiety and pain, and enhance immunity. Lind-Kyle adds that different types of mediation can help regulate the four main neurotransmitters: acetylcholine, dopamine, GABA and serotonin.
Staying creatively engaged with the world also helps keep the brain young. “If you visit a foreign city you learn so much in a day compared to an average day at home,” says Barry. Unlike children, whose brains grow just by being exposed to something new, adults need to be active learners to realize the benefits of novelty. “When you’re an adult the brain is pickier,” Barry says. “If it doesn’t matter to you, it doesn’t matter to your brain. I sing in a choir; if I’m not interested in the songs, I’m not going to retain that information.”
Adults are also prone to falling into ruts. “As you get older your world shrinks; you do less, it shrinks more. It’s a negative feedback loop,” Barry explains. “You have to challenge yourself to learn new things—the more new things you learn the more you’ll keep.” Researchers have found that older people who tutor children show reduced signs of brain aging (Journal of Gerontology 12/09). One way to protect your brain is to not become overly dependent on technology. Barry sees it with her students and their calculators; “they’ve lost the ability to do simple calculations in their heads,” she says.
Exercise enhances neuroplasticity. “It improves existing connections, makes new ones and helps stimulate the production of new brain cells,” says Mark Hyman, MD, founder of the Ultra
Wellness Center in Lenox, Massachusetts and author of The UltraMind Solution (Scribner, www.ultrawellness.com). He recommends walking 30 minutes a day.
A flexible brain requires proper nutrition, and many researchers believe that the Mediterranean diet—with its whole grains, abundant olive oil, variety of vegetables and emphasis on fish—is ideal for maintaining brain health. One investigation found a 40% reduction in Alzheimer’s risk among people whose eating habits followed this pattern, especially if they were physically active as well (JAMA 8/12/09).
One reason the Mediterranean diet is so healthy lies in its omega-3 fatty acid content. “Our brains don’t work without omega-3 fats. Period,” Hyman says. The body uses omega-3s to build myelin; this substance coats nerve cells like plastic coats a wire, which enhances signal transmission. Omega-3 is also required to build the membranes that surround cells, including neurons, along with substances called phospholipids (available as phosphatidylcholine, or PC, and phosphatidylserine, known as PS).
One omega-3, DHA, may improve mental function in middle age (Journal of Nutrition 2/24/10 online). Adequate amounts of omega-3 also help dampen the kind of low-level chronic inflammation linked to many degenerative illnesses, including Alzheimer’s.
Deficiencies in vitamin D are prevalent throughout the US population. Hyman says such deficits have been linked to a number of ailments, including depression and dementia. Being deficient in B vitamins—especially vitamins B6 and B12 along with folic acid—is another factor in cognitive decline. This vitamin trio helps control high levels of homocysteine, an amino acid associated with greater risk of dementia and cardiovascular disease.
A number of supplements may be helpful in forestalling aging’s effects on the brain. “Gingko biloba is a powerful brain antioxidant,” says Hyman, noting that Chinese healers have used ginkgo for thousands of years to enhance memory. Hyman says that huperzine A, derived from Chinese club moss (Huperzia serrata) has “shown significant benefits in dementia with few side effects.”
Huperzine A has reduced brain inflammation in animal studies (Journal of Neuroscience Research 3/10). In humans it is thought to prevent malfunctioning in mitochondria, which are responsible for cellular energy production (Chemico-Biological Interactions 9/25/08; for more information on energy and the brain, see the box above). India has one of the lowest Alzheimer’s disease rates in the world; many researchers believe the key may be curcumin, the principal ingredient in the curry spice turmeric. Curcumin has demonstrated an ability to fight formation of the plaque deposits within the brain that occur in Alzheimer’s.
Thanks to our flexible brains, mental decline isn’t an inevitable part of aging. But staying sharp requires a conscious effort. “We have an ability to change throughout life—it’s always there,” Barry says. “If you don’t use it you will lose it.”
Needles on the Brain
Acupuncture, the Chinese practice of using needles to affect flows of energy (qi) within the body, both puzzles and fascinates scientists in the US. Researchers associated with the National Center for Complementary and Alternative Medicine (NCCAM; http://nccam.nih.gov) aren’t sure exactly how acupuncture works—“we don’t currently have a ‘qi meter,’” as Harvard neuroscientist Vitaly Napadow, PhD, LAc, puts it—but that hasn’t stopped the flood of studies into acupuncture’s benefits.
“What we’ve learned so far is that the most promising area for using acupuncture is pain,” says Richard Nahin, PhD, MPH, NCCAM’s Senior Advisor for Scientific Coordination and Outreach. This ancient healing art appears to affect pain centers in the brain. For instance, carpal tunnel patients in Napadow’s research who underwent acupuncture showed greater activity in an area of the brain called the hypothalamus and reduced activity in the amygdala; both areas help process emotion, long-term memory and persistent pain. In other studies, acupuncture has improved function in people with knee osteoarthritis and brought relief to people with lower back pain (Annals of Internal Medicine 12/21/04, Archives of Internal Medicine 5/11/09).
To find an acupuncturist in your area, contact the American Association of Acupuncture and Oriental Medicine at 866-455-7999 or www.aaaomonline.org.