YOUNG & OLD
Brain scans reveal the different ways young and old brains process information. When young and old test subjects look at pictures, the young brains experience most activity in the right hemisphere, in a region known as the right visual cortex. Older brains activate the visual cortices of the right and left hemispheres about equally. When asked to observe a picture and hold the image in their mind, young people activate their frontal cortex more than older adults, whose brain lights up more diffusely ill the temporal and parietal lobes.
10 PERCENT MYTH
ITS A MYTH that humans use only a tenth of their brain. Perhaps this error can be traced to author Norman Vincent Peale, who wrote (without attribution) that people use 10 to 20 percent of their mental capacity. Or perhaps the source lies with the observation that humans sometimes recover from extreme brain damage. Mathematically, it’s impossible to figure a percentage of active or inactive neurons in a human brain. Brain scans don’t keep a tally of neurons as they fire, and nobody knows exactly how many nerve cel ls exist in a healthy adult brain. So the numerator and denominator of any fraction representing the activity of neurons in the brain are mere guesses.
Failure to remember names IS an example of decreased memory performance of the aging brain. Although it’s common for people of all ages to struggle with names from time to time, the problem becomes pronounced among the elderly. Theories about the increased difficulty of storing and retrieving names from long-term memory focus not only on the general decline of such memory function of the aged, but also on the lack of context that would more easily call names forth. A person’s name usually has no connection with how he or she looks, dresses, or talks. Thus, there’s no associative link to aid memory retrieval, as there would be for, say, a woman named Rose who has pink hair. Without such a link, names have no ready place for storage in memory. Futhermore, elderly brains with their overtasked working memory may be more prone to distraction during introductions. If you hear someone’s name for the first time while simultaneously thinking about other things, it’s likely you’ll have more trouble remembering it.
There is good news, however. When an elderly brain gets regular mental exercise and remains free of disorders such as dementia, it maintains capacities for abstract and analytical thinking, expression, and other higher functions. If memory remains intact, vocabulary and knowledge of the world expand with time, and communication can become more sophisticated. The storehouse of wisdom accumulated in a well-aged brain becomes a treasure of experience built up over a lifetime. An elderly brain may not react as quickly as a youthful one, but it can be just as complex, or even more so.