The
Aging Brain & Designs for Strong Minds™
By the age of 75, the average adult has half the brain
cells in the occipital cortex (visual area) of the average
20-year-old. This massive loss may be due in part to the
effect aging has on our eyes. With time, the cornea (the
transparent fluid-filled bag in front of the lens) changes
in molecular structure. As a result, light rays are bent
and scattered more haphazardly which we experience as blurred
vision. The shape of the cornea also changes. It flattens
so that, by age 60, many of us require the help of eyeglasses
or magnifying lens for close, detailed work.
The iris (which controls the size of the pupil) is also
altered by aging. Its fibers may atrophy so that the size
of the pupil is reduced. This means fewer photons can enter
our eyes, requiring more light for close activities such
as reading. The atrophy also reduces flexibility so our
eyes cannot adjust as quickly to sudden change in light
intensity. In other words, we become less sensitive to
gradual contrasts in light or shadow.
As we age, our eyes grow more and more lens tissues. Because
previous tissues are not removed, the new layers compress
the older ones to the center, thus increasing the lens'
diameter. Between 20 and 70 years of age, the average lens
triples in mass. This is another cause of farsightedness.
Moreover, the lens takes on a yellowish hue. It becomes
increasingly difficult to distinguish greens, blues, and
violets. And yellow itself becomes less "bright." Our color
perception is altered.
Of course, these changes don't happen overnight. The changes
are so gradual that many times we're more apt to blame
something in the environment ("They don't make lights as
strong as they used to") or lose interest in activities
we once enjoyed than to recognize that our perceptual ability
has altered.
Contrast the devastation of the occipital cortex with
the vitality of the prefrontal cortex (associated with
memory). In most people, the prefrontal lobe shows virtually
no loss of brain cells with age. Some studies suggest that
memory impairment in the aged is not so much loss of specific
facts as it is a reduced ability to readily retrieve what
is known. This may be due to a reduction or disconnection
of neural pathways.
This raises an interesting possibility regarding the preservation
of mental facilities as we age. It is known that an active
social life greatly contributes to the maintenance of a
healthy brain. Perhaps part of the reason is that interaction
with other people provides increased sensory stimulation
that keeps brain cells alive and active. It is not the
stimuli itself that matters, but the way the stimuli is
processed through intentional interaction. In other words,
when we relate to other people, we have to engage our frontal
lobes (the judgmental and decision making part of the brain)
to organize the sensory stimuli we're receiving and to
act upon it.
With this possibility in mind, Designs for Strong Minds™ (DSM) programs can provide systematic, progressive training
of the visual systems through intentional behavior. DSM
does this with graphic puzzles organized to challenge and
enhance cognitive and relational thinking skills such as
comparative and sequential thinking, part-whole relationships
and categorization. In effect, the puzzles encourage participants
to exercise the muscles that are most likely to atrophy
with age—the ones that enable us to note and observe fine
details that enrich our lives. Consequently, DSM helps
make people aware of what they have gradually been missing.
© Copyright 2004 Donalee Markus, Ph.D. & Associates |
