Anti aging guide

The Facts About Aging Brain Problem



Does the brain deteriorate in later life of older people and how to solve the problem?

There has been a wealth of experimental work on the testing of intelligence at various ages, much of which is hampered by the difficulty of defining intelligence in any universally acceptable terms except ‘that quality which is measured by intelligence tests’! And although many and various are the tests which have been designed to assess ‘mental ability’ or intelligence quotient (IQ), their use among older people is further bedeviled by the fact that they are usually primarily intended for use among children and adolescents. In tests incorporating practical information more appropriate to the lifestyle and culture of older people, it is often found that scores increase with age.

More than almost any other investigation, IQ comparisons at different ages require longitudinal repetitions rather than cross-sectional surveys. If different age-groups are compared, they will represent groups of people separated by huge differences of cultural background in terms of education, experience, expectations, way of life, media exposure, and habits, and are thus not comparable. Longitudinal studies in which the same individuals are retested over long periods of time overcome these objections but clearly present formidable practical difficulties.

Nevertheless, some studies of this type have been conducted. In one so-called ‘cross-sequential’ investigation, the same subjects were re-assessed seven and fourteen years after initial testing, and at the same time new subjects of all ages were introduced into the survey and assessed at the seventh and fourteenth years. The outcome suggested that, on the whole, there was a significant degree of decline after the age of 67, and this became substantial between the ages of 74 and 81. But differences between individual subjects were as large as differences due to aging, and there were also tremendous individual differences in the rate of change.

Some recent research in Cambridge illustrates some of these points. An elderly group was compared to a young group in a whole batch of tests of learning, memory, reaction time, and decision-making, and found to perform less well. But the range was so much larger in the older subjects that in each test many of them did better than the average for the young people (mainly undergraduates), and quite often one of the older ones would actually come top. There was thus a great deal of overlap, and it was generally found that the elderly people who performed badly were in poor health. Perhaps it is worth briefly looking at some specific characteristics.

Between the ages of 20 and 60, the reaction time seems to fall by an average of 20 per cent in tasks of psycho motor function involving,for example, pressing the correct button in response to flashing lights of different colors. This appears to be due to slower decision-making in the brain, and not to changes in the peripheral motor or sensory systems. The older subjects seem to opt for accuracy rather than speed, and take longer in order to ensure that the response is correct. There is again, a tremendous overlap between the age groups, and speed is particularly affected by ill-health, but some decline appears to be usual from the 50s on.

Once again, on the whole the older subjects are less successful at solving complex problems. It is arguable whether this is due to lower IQ, to slower information processing, or to greater rigidity of thought. It is said that fluid ability declines, but crystallized ability improves with age. What is clear is that the elderly are more easily ‘thrown’ by the inclusion of irrelevant and redundant information. It has been demonstrated that older engineering workers have more difficulty interpreting involved working drawings.

Tests of vigilance often indicate that attention is maintained at as high a level in older subjects as in younger ones until fatigue sets in at a rather earlier point. Distract ability is generally greater among older people: it is everyday experience that we more readily lose the thread of a program on the car radio when the traffic thickens or there is a somewhat stressful junction. The alternative is selective inattention to the road, which is why we advise older motorists against a car radio or a loquacious companion.

Some differences between the ages have been shown by cross-sectional studies and are therefore open to doubt. There may be a deficit in short-term memory as demonstrated by recall procedures, which involve retrieval as well as the initial reception and storage. This is much less apparent when recognition of a recently displayed pattern only is involved and does not require retrieval. Remote memory remains relatively unimpaired, but, contrary to popular belief, is not necessarily better than in the young.

Cross-sectional studies merely illustrate the increasing pace of sociocultural change which is now beginning to render people obsolescent in their 50s!

Performance testing does show some decline, but this is due to a variety of factors. In the elderly, it is easily adversely affected by fatigue. It is also affected by cautiousness, so that many do not perform to their full potential due to extraneous factors. For instance, it has been shown that there is little reduction in the ability to hear and understand sentences between the 20s and the 70s so long as the listening conditions are favorable. If the hearing conditions are poor, people experience difficulties in their 30s which become marked in the 50s.

There seems to be some decline in intellectual function which does not begin early, does not affect all aspects of the intelligence, and is not universal and inevitable in all the elderly. 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.

In one Australian study, 80 people between 63 and 91 received weekly German lessons. After three months, half of them passed an examination normally attempted by schoolchildren after a three year course. We have no direct evidence that continued use of the mental faculties ensures the preservation of mental health, but it certainly cannot be bad for the health, and it certainly can enrich our later years.

Posted by Carol Hudgens - April 29, 2012 at 8:37 am