| Sure enough, pretty soon the word
or name you're looking for obligingly returns to consciousness.
Brains do change with age. We lose brain cells, or neurons - around
50,000 of them a day over a lifetime. This may sound terrible but it works out at merely
3% of the total by the age of 80, since we start off with a good ten billion. We also,
over the years, lose some of the chemical messengers or neurotransmitters which
carry information from one nerve cell to another.
Sounds like bad news, but the brain works in mysterious ways. If one neuron fails, its
neighbours can compensate. Scientists have found that neural networks take different paths
in different age groups, though performances are the same.
From about the age of 50, reaction time, memory, learning ability,
problem-solving and decision-making may begin a decline. Blood supply to the brain can be
reduced by 20 -25% between the ages of 30 and 70. Reaction time, which stems from messages
from brain to body, is thought to slow down by 30-40% in old age. This means we will be
slower to jam on the car brakes when required or to hit a tennis ball at the crucial
moment.
But again all is not what it seems. When different age groups are compared, there is a
great overlap in ability. Ill health, genetic make-up, physical or mental inactivity
contribute greatly to variation in performance in older people.
From the early 60s to the mid-70s, there is normally a decline in some but not
all abilities in some but not all people. After the age of 80, however, a decline
is the rule.
Which people stay mentally younger longer? We get some clues from rats.
When deprived of stimulation, the brains of rats shrink, claims Marion Diamond of the
University of California at Berkeley. But deprived rats, given a variety of toys, wheels
and ladders and a month in the company of fellow rats, gain extra blood supply in the
brain and an increase in brain size.
The same may be true of ageing humans. Those who regularly play bridge or do crossword
puzzles score better in mental tests than those who rely on bingo to sharpen their wits.
The use-it-or-lose-it dictum applies as much to mental as it does to physical power, which
is why this series is including brain training exercises.
There are some ways in which getting older means getting better. Experience
really does bring better judgement. If we slow down when decision-making, it is partly due
to a desire for accuracy rather than speed. We know more and therefore need more time to
think. We opt for the considered and careful and trust less in the risk-taking hopeful.
Older people know when they feel tired and begin to lose attention. Their threshold may be
lower than that of younger people, but they are more likely to give in gracefully than
overstretch themselves.
Getting older can mean getting cleverer. When experienced typists of college age
were compared with a similarly accurate group over 60, the young were expected to be
faster and more nimble fingered. In fact, both groups were equally fast. But the older
typists had developed clever, time-saving strategies which involved fewer finger movements
and reading ahead in the text that made up for their slower reaction times.
Experience means that we can calculate when to cut corners without even thinking about
it. We continually evaluate and refine. We also get to think in a process known as
'chunking', which means we lump specialised knowledge together till it seems to be a
single piece of information. The first few times you make an omelette or do a serious of
exercises you have to refer to instructions. With practice, you carry the whole thing in
your head as a single operation. That's chunking.
And another thing. Retired professionals, especially teachers and journalists,
score higher in vocabulary tests than college students. Not surprising, given those years
of reading, listening, viewing, talking, writing. Exercise the brain cells and they'll
serve you well.
Eight ways to age-proof your mind
*1. Do things your way, not the young way - and that means giving yourself time
without pressure when doing, thinking and deciding
*2. Plan one project at a time, with minimum interruption - that's the way we
work best as we get older, and it's neither better nor worse than younger methods
*3. Retirement doesn't mean stopping thinking. Take up new interests that
exercise memory, reasoning power and problem-solving. (That doesn't necessarily mean
having to get bookish or academic. Dance classes as well as language courses can exercise
memory; car maintenance or clothes-making involve reasoning power and problem-solving. And
remember, take the learning on slowly. You'll retain it longer)
*4. Playing cards and doing crosswords keep the mind sharpened
*5. New experiences, such as holidays in unfamiliar places, are stimulating.
Read up the history before you go and write up the adventure when you get back
*6. Don't say all you want to do is hang around old friends. Get out and meet
new people. Make an effort to get to know them
*7. If you have grandchildren, teach them new tricks. If you haven't, borrow
someone else's
*8. Don't be put off by new gadgetry and ever-changing technology. You may take
longer to master it than the average schoolkid, but you'll get there in time. And after
all, here you are, logging onto laterlife.com on the net. That's the sign of an active
mind.
Coming soon - ways to improve memory |
How to age-proof your mind 
