Science
Daily, October 15, 2008
For children with Attention Deficit
Hyperactivity Disorder (ADHD) tasks that require concentration
such as doing homework or taking a test can be very difficult. A
simple, inexpensive remedy may be a "dose of nature."
A study conducted at the University of Illinois shows that
children with ADHD demonstrate greater attention after a
20-minute walk in a park than after a similar walk in a downtown
area or a residential neighborhood. The study, conducted by
child environment and behavior researchers Andrea Faber Taylor
and Frances E. Kuo was published in a recent issue of the
Journal of Attention Disorders.
"From our previous research, we knew there might be a link
between spending time in nature and reduced ADHD symptoms," said
Faber Taylor. "So to confirm that link we conducted a study in
which we took children on walks in three different settings
one especially "green" and two less "green" and kept
everything about the walks as similar as possible."
Some children took the "green" walk first; others took it second
or last. After each walk an experimenter, who didn't know which
walk the child had been on, tested their attention using a
standard neurocognitive test called Digit Span Backwards, in
which a series of numbers are said aloud and the child recites
them backwards. It's a test in which practice doesn't improve
your score.
"We compared each child's performance to their own performance
on different walks," said Faber Taylor. "And when we compared
the scores for the walks in different environments, we found
that after the walk in the park children generally concentrated
better than they did after a walk in the downtown area or the
neighborhood area. The greenest space was best at improving
attention after exposure."
"What this particular study tells us is that the physical
environment matters," said Kuo. "We don't know what it is about
the park, exactly the greenness or lack of buildings that
seems to improve attention, but the study tells us that even
though everything else was the same who the child was with,
the levels of noise, the length of time, the time of day,
whether the child was on medication if we kept everything else
the same, we just changed the environment, we still saw a
measurable difference in children's symptoms. And that's
completely new. No one has done a study looking at a child in
different environments, in a controlled comparison where
everything else is the same."
The sample size was relatively small mostly because the
logistics were a nightmare to coordinate. "Because we kept
everything the same, the children all went to the same park and
walked through the same neighborhood and downtown area. The
testing location had to be close by so that there wasn't a lot
of lag time between going for the walk and taking the
post-test," said Faber Taylor. "And each child was always paired
with the same adult guide for their walks, and all the children
were tested by the same tester."
Kuo said that the variables of the study were very hard to
control. "We started with a much larger sample size. But when we
threw out all of the things that could go wrong the weather
wasn't good one day, the child came late, or came medicatedwhen
we threw out all of those, it left us with this relatively pure,
clean sample to work with."
Faber Taylor added that their confidence in the findings from
this study is bolstered by findings from other studies. "Because
we have results from a national study which looked at over 450
children, we can have more confidence that this relationship
between natural settings and improved attention is true not just
for the children in this study." She said that the larger study
included children from all over the United States, representing
a wide range of ages, different community sizes, and both with
and without hyperactivity. "The findings from the national study
give us some confidence that this relationship applies to all
children with ADHD."
Kuo emphasized that this study involved an objective test of
attention, not just on children's or parents' impressions.
During the walks, all of the children were unmedicated -- those
of the participants who normally took medications to control
their ADHD symptoms stayed off their medications on the days of
the walks. Interestingly, Faber Taylor and Kuo found that a
"dose of nature" may be as helpful -- at least for a while -- as
a dose of stimulants. "We calculated the size of the effect in
our study and compared it to the size of effects in a recent
medication study," said Faber Taylor, "and we were surprised to
see that the dose of nature had effects the same size or even
larger than the dose of medication." What remains to be seen is
how long the effects of a dose of nature last.
"Some of the previous survey research suggests a relationship
between children who regularly play in green spaces and how
severe their symptoms are. Children who have regular exposure to
green spaces have milder symptoms overall. So that's hinting
that there may be a persistent effect," said Kuo.
She said that while there are hints that the regular doses of
nature work long term that you can expose a child to the same
green outdoor settings day after day and still get a benefit
the science isn't advanced enough to give parents a strict
formula. "We can't say for sure, 'two hours of outdoor play will
get you this many days of good behavior,' but we can say it's
worth trying, and we can say that as little as 20 minutes of
outdoor exposure could potentially buy you an afternoon or a
couple of hours to get homework done," said Kuo. "One reason we
believe this is that if the effect were short-lived, we don't
think that parents would have so consistently observed it. But
they do. They report it over and over. And they report it
independently. So, in the larger study with over 450 kids, we
asked 'what's your kid like after watching TV or after playing
outside' and none of the parents know what any of the other
parents are telling us, but they overwhelmingly agree."
Faber Taylor believes it would be easy to add a dose of nature
to a child's routine. "I could imagine parents hearing about
this research and immediately applying it just trying it out
taking their child to the park either when their child's
symptoms are exacerbated or as a regular routine. It's not that
hard to incorporate, especially if they have a green backyard or
if they can get to a neighborhood park. Again, we can't say for
sure that it would work for any given child but there's
probably very little risk involved in encouraging your child to
play outdoors and seeing if their symptoms improve."
She also says that the benefits of a dose of nature don't apply
just to children with ADHD. "We're all on a continuum of
attention so this study has implications for all of us," said
Taylor. "ADHD is just at the far end of attention functioning,
but there're plenty of us who fall somewhere close to that end
of the continuum, and we all experience times when we're
mentally fatigued times when we're less able to focus and do
tasks and get easily distracted. The evidence suggests that
natural settings can benefit everyone, even children (and
adults) who have not been diagnosed with ADHD."
This material is based upon work supported by the National Urban
and Community Forestry Advisory Council, U.S. Forest Service
under award No. 00-DG-11244225-354, and the Cooperative State
Research, Education and Extension Service, U.S. Department of
Agriculture, under Project No. ILLU-65-0370
back to the top ~
back to Breaking News
~ back to
What's New
|