Age doesn't cripple learning
An older person can usually learn just as many new things as a younger person; it just may take longer. For some reason, a lucky 20 percent of adults suffer no substantial loss in their rate of learning as they grow older. The rest of us, however, experience modest declines in mental agility, losing some memory functions -- a key to learning -- and taking longer to process information. How fast people learn as they age depends on whether the subject matter is familiar to them. Researchers say that older people often learn new material in a familiar subject area as quickly as younger people do. If, however, the subject matter is new to them, more time is needed. In one study, two groups of people with no computer experience were taught a word-processing program. The group of people aged 65 to 75 took longer to learn the program than the 18- to 30-year-olds. What accounts for the slowdown in learning is still under study. Older people may simply have more memories to sort through. A slowing of motor responses may affect how quickly they learn skills that require movement. Or comprehension could be hampered by a gradual loss of communication between parts of the brain. The good news is that a slower rate of learning doesn't necessarily mean a reduction in the amount of material that can be learned. By the end of the computer study, there was no significant difference in levels of expertise between the two age groups.
Swinging your arms:
Why do we swing our arms when we walk? Most researchers agree that arm-swinging is probably a muscular "memory" left over from the days when we walked on all fours. Leonardo da Vinci may have been the first to remark on this connection about 500 years ago. Most four-footed animals, he wrote, move their front and hind legs in a pattern identical to a human's walk. Now that we've evolved to upright walking, though, we don't bounce our arms back and forth just because there's nothing else for them to do. In one study, walkers whose arms were strapped to their sides still showed movement in their shoulders, suggesting that swinging is necessary to normal walking. Some experts say we swing our arms to make strolling smoother, possibly reducing the overall energy used in walking. As we walk we put one foot ahead of the other. That forward motion twists the pelvis. When we swing the opposite arm forward, it's to counteract this twist so we don't end up turning sideways. When walkers in the study were asked to walk with their arms matching their step, their bodies turned from side to side. Their gait, which most found difficult to maintain, looked like a ridiculous dance.
AIDS in the blood supply:
Even the sharpest screening tests can't completely eliminate the threat of AIDS from the U.S. blood supply. That's because there is typically at least a several-week lag time between infection and the production of telltale blood markers, and some HIV infections may be silent for years. But an encouraging new study from the University of California in San Francisco (UCSF) suggests that even in cities where AIDS is prevalent, the risk of transmitting the virus through transfusions is only about one in every 61,000. That's about 50 percent lower than a widely accepted estimate published last year and is probably more reliable, says UCSF's Girish Vyas, because it's the first big study to directly check donated blood for the virus.
Ringing in the ear:
That ringing in your ears is tinnitus, an annoying noise that sometimes -- though certainly not always -- indicates permanent hearing loss. Exposure to loud noises, such as gunshots or rock concerts, can temporarily injure the tiny sound-sensing cells in your inner ear, causing them to send random messages along the hearing nerve. Your brain interprets these messages as buzzing, hissing, roaring or ringing sounds, which become more noticeable in a quiet setting. Repeated exposure to loud noise can lead to permanent tinnitus and hearing loss. Ear infections, allergies, injuries and tumors can also cause temporary tinnitus, which may become permanent if not treated. To find out why your ears are ringing, especially if it came on suddenly, see an otologist or otolaryngologist. Even if your tinnitus is diagnosed as permanent, you can keep it from getting worse by wearing earplugs when you're exposed to loud sounds.