Neural Aging Walks Tall: Aerobic activity fuels elderly brains, minds
Bruce Bower
Seniors interested in pumping up their brains and maintaining an attentive
edge might consider taking this inexpensive prescription: Go for a walk every 2
or 3 days. Don't sweat it, but make an effort. Limit each walk to between 10 and
45 minutes.
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STEPPING SMARTLY. Regular walking may hold neural benefits for
seniors.
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That's the conclusion, at any rate, of two new studies that demonstrate for
the first time in people that physical fitness, whether achieved on one's own or
through a brief aerobic-training course, induces brain changes associated with
improved performance on an attention-taxing task.
"Even moderate cardiovascular activity of the sort that is within reach of
most healthy older adults results in improved neural functioning and may help to
extend or enhance independent living," says neuroscientist Arthur F. Kramer of
the University of Illinois at Urbana-Champaign. Kramer directed the new studies
with his colleague Stanley J. Colcombe.
Prior research showed that mice score higher on tests of learning, memory,
and attention after regularly exercising on a running wheel for several weeks.
In the animals, this training boosts the brain's blood supply, increases
connections between neurons, and promotes the development of new brain cells.
Moderate exercise works similarly in people, Kramer and Colcombe's team
reports in an upcoming Proceedings of the National Academy of Sciences.
The scientists first assessed physical fitness in 41 older adults, ages 58 to
77, after each walked 1 mile. Participants then performed an attention task in
which they viewed arrays of five left-or-right-pointing arrows and used computer
keys to indicate whether the central arrow pointed left or right.
During testing, a functional magnetic resonance imaging (fMRI) scanner
measured the rate of blood flow in specific regions of each volunteer's brain.
Adults identified as particularly fit made judgments about the arrows faster
and with equal accuracy compared with their less-fit peers. Moreover, the fMRI
data show that highly fit seniors exhibited intense blood flow in frontal-brain
areas implicated in allocating attention and minimal neural activity in a
frontal region that usually perks up in situations of indecision.
In a second study, 15 elderly volunteers accomplished attention tasks
markedly faster after completing a 6-month aerobic-training course than they had
before the course started. Participants gradually built up to walking for 45
minutes at a moderate pace three times each week. By the end of the study, these
volunteers' brain activity resembled that of highly fit seniors in the first
study.
In contrast, 14 seniors who completed a 6-month course of stretching and
toning exercises, but not aerobic exercise, showed little improvement on the
attention task. Their brain activity was similar to that of less-fit seniors in
the first study.
Colcombe and Kramer's studies are "an impressive achievement," remarks
psychologist Timothy Salthouse of the University of Virginia in Charlottesville.
Further research should examine whether aerobic training enhances seniors'
performance on other psychological tasks and whether such improvements confer
any advantages in daily life, Salthouse says.
Kramer and his colleagues are now testing whether aerobic training might
improve seniors' driving skills.
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References:
Colcombe, S.J., A.F. Kramer, et al. In press.
Cardiovascular fitness, cortical plasticity, and aging. Proceedings of the
National Academy of Sciences.
Further Readings:
Colcombe, S., and A.F. Kramer. 2003. Fitness effects on the
cognitive function of older adults: A meta-analytic study. Psychological
Science 14(March):125-130. Abstract available at http://www.blackwell-synergy.com/links/doi/
10.1111/1467-9280.t01-1-01430/abs/.
Sources:
Stanley J. Colcombe
The Beckman Institute
Neuroscience
Program
University of Illinois, Urbana-Champaign
Urbana, IL 61801
Arthur F. Kramer
The Beckman Institute
Neuroscience
Program
University of Illinois, Urbana-Champaign
Urbana, IL 61801
Timothy A. Salthouse
Department of
Psychology
University of Virginia
102 Gilmer Hall
P.O. Box
400400
Charlottesville, VA 22904-4400
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