It's all in your head: slowing the process of mental aging

Although most people know mental abilities decline with age, the, increasing public awareness of Alzheimers disease sometimes makes us question our own thinking and reasoning abilities. Consequently, people often overestimate the degree and rapidity of mental performance declines. Any instance in which one cannot immediately recall a familiar name, solve a logical problem or remember something recently learned suddenly becomes an ominous sign. Psychologists have extensively researched how mental abilities change with age and what we can do to slow or, in some cases, reverse the process. Perhaps foremost among these studies is the ongoing Seattle Longitudinal Study, conducted by psychologist K. Warner Schaie, which has examined the cognitive aging process in hundreds of subjects since its inception in 1956.

Basic Mental Abilities

The following seven basic mental abilities have been identified to change with age by psychologists:

* Verbal meaning: The ability to understand the meaning of spoken and written material.

* Word fluency: The ability to use words to write and talk.

* Verbal memory: The skill to memorize and recall verbal material for both short and long periods of time.

* Inductive reasoning: The capacity to recognize and understand novel concepts, solve logical problems, foresee difficulties and plan ahead.

* Spatial orientation: The competence to visualize objects' orientation in space and perceive the relationships among those objects.

* Numeric ability: The ability to accurately solve simple math problems rapidly and understand numerical relationships, particularly information presented in graphs or tables.

* Perceptual ability: The ability to carry out simple tasks involving visual perception with speed and accuracy, such as locating a friend in a crowd or judging the relative size of several objects.

Scientists know some abilities improve as we get older while others inevitably decline. However, cognitive abilities do not falter as early as many people anticipate. In fact, significant declines do not even begin to appear until after age 60 and are not appreciable until the late 60s and early 70s. For instance, fewer than one in 20 individuals, between the ages of 65 and 69, will suffer from serious memory lapses. By the mid 70s, however, significant decrements have typically occurred to all abilities. These declines are small at first but become increasingly larger as one reaches the 80s. Noticeable declines prior to age 60 often indicate some type of pathology.

Below, Table 1 illustrates the mental ability changes individuals can realistically expect during each decade of their adult lives.

Typically, declines occur in a stair-step, rather than gradual, fashion. An unfavorable experience, such as an accident or illness, often triggers sharp drops. For example, my mother's mental abilities decreased normally until her late 80s, when she fell and broke her hip. Afterwards she displayed a sharp drop in many mental abilities, particularly short-term memory. Such marked decreases following an accident are not uncommon and the abilities usually stabilize quickly at the lower level, resisting further decline at the same rapid rate.

Scientists have recognized the importance of genetic factors in mental decline. Examining declines in your parents and grandparents often offers a glimpse of what you might experience. Your overall health also predicts how gracefully you will age mentally. Cardiovascular disease, diabetes, tumors and even arthritis are associated with faster declines in mental abilities. Paradoxically, these same illnesses can also be positive indicators. For example, people who survive cancer, experience a late onset of arthritis or cardiovascular disease have been found to have higher mental functioning levels in old age. Encouragingly, individuals who engage in lifestyles that prevent or ameliorate such illnesses and other accidents have significantly higher cognitive functioning during the aging process. This includes regular exercise, seeking early medical care for illnesses, conscientiously following professional medical advice and avoiding risky activities, such as motorcycle riding or hang gliding.

Reducing the Degree Of Mental Decline

While some decline in mental abilities is inevitable during your 70s and 80s, you can often regulate its extent. Although genetic factors are beyond your control, environmental factors within your control play an even more important role.

Scientists have observed that people from higher socioeconomic levels enjoy increased levels of mental functioning throughout their lifetimes. Although this may be due, in part, to their access to better health care, this does not fully explain it. These people also enjoy higher levels of education and occupations which require complex problem solving with comparatively little routine or repetitive work tasks.

You may not have been born into a wealthy family, but you can emulate their lifestyle. Strive to maintain a complex and intellectually stimulating environment throughout your lifespan. This can be accomplished through extensive reading, traveling, attending cultural events, participating in continuing education activities, clubs and professional associations. Even keeping families intact appears to help inoculate against mental decline.

Besides relationships, personality styles also predict mental decline. Are you a creature of habit? Do you adhere to a rigid schedule in your daily life? Recent research suggests individuals who develop rigid response patterns suffer much sharper declines in mental abilities than those with more flexible lifestyles. Subtle variability and complexity in your daily routine can protect your mental skills.

Your spouse or partner also plays an important role. A high correlation is observed in the mental abilities of married couples. Often, a sharp decline in one partner will be followed by a similar decline in the other. More encouragingly, if one of the partners maintains a high level of mental functioning, it appears to preserve or even increase the level of functioning in the lower functioning partner.

Avoid the Self-Fulfilling Prophecy

Sadly, merely believing one's mental abilities are failing can often result in experiencing such a decline. This frequently occurs when individuals limit their activities to compensate for perceived declines. If you believe you are not as mentally sharp as you used to be, see it as a call to action rather than a retreat. Pursue activities, such as those suggested earlier, which engender complexity and diversity in your social interactions and thought processes. Research clearly indicates cognitive decline occurs more from disuse than physiological or neural deterioration.

Reversing the Process

The most encouraging research findings to date indicate declines in mental abilities are often reversible. Schaie's Seattle research team gave older individuals training in problem solving, inductive reasoning and spatial orientation tasks. Two-thirds demonstrated significant improvement in abilities after only five hours of training. In fact, nearly half of those individuals, who had suffered significant declines during the previous 14 years, regained their levels of functioning prior to the decline.

Changes in mental abilities are inevitable, but for the majority of individuals, such declines are modest. More importantly, continuing scientific studies demonstrate easy ways in which we can greatly moderate aging's effects on our mental abilities.

Examples of some of the training exercises used in the Seattle Longitudinal Study

Reasoning exercises: Individuals are shown a series of letters, numbers or words that form a series based on one or more rule(s). The person is trained how to discover the rule(s) and find the term that should come next in the series. For example: ab x cd x ef x gh x --, January, March, May --, and 6, 11, 15, 18, 20,

Spatial orientation exercises: Individuals are trained to visualize and mentally manipulate objects in two or three dimensions. For example, each individual is asked:

Which of the following letters is the same as the letter Q

[ILLUSTRATION OMITTED]

Which of the following items is the same as this watering can

[ILLUSTRATION OMITTED]

Table 1. What to Expect at Different Age Levels

AGE   COGNITIVE ABILITY LEVEL

20s   Most mental abilities are above average and improving, including
      verbal meaning, spatial orientation, inductive reasoning, number
      skills and word fluency. Verbal memory remains stable.
      Perceptual ability is very good but starts to show initial
      declines.
30s   Competencies in verbal meaning, verbal memory, spatial
      orientation and inductive reasoning increase. Word fluency
      remains stable while number skills begin to decline.
      Perceptual ability continues to diminish.
40s   Verbal meaning, verbal memory and inductive reasoning improve.
      Spatial orientation and word fluency remain stable. Number
      skills and perceptual ability continue to decrease.
50s   Verbal meaning, verbal memory and inductive reasoning remain
      stable. Modest declines in numeric ability, perceptual ability
      and word fluency continue.
60s   Modest, barely detectable declines begin in all mental
      abilities. The sharpest decline occurs in numeric ability.
70s   Continuing moderate declines in all cognitive abilities.
80s   Increasing declines in all cognitive abilities.

References

Arbuckle, T.Y., Maag, U., Pushkar, D. and Chaikelson, J.S. "Individual differences in trajectory of intellectual development over 45 years of adulthood." Psychology and Aging, 1998, 13,663-5.

Schaie, K.W. Intellectual Development in Adulthood: The Seattle Longitudinal Study. New York: Cambridge University Press, 1996.

Rick M. Gardner holds a Ph.D. in experimental psychology. He has authored two textbooks and numerous scientific articles in a variety of areas in psychology. Gardner is currently professor emeritus of psychology at the University of Colorado in Denver.

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