Author: Dr. David Rabiner
Source: Attention Research Update, v62
Date: June 2002
Can contact with nature enhance attentional functioning in children with ADHD? Recently, I came across an interesting and unusual study in which this hypothesis was explored (Taylor et al., (2001). Coping with ADD: The surprising connection to green play settings. Environment and behavior, 33, 54-77.)
The notion that exposure to nature might improve attention problems in children is based on the Attention Restoration Theory, which proposes that natural environments can assist attentional functioning. According to this theory, humans have two types of attention: voluntary attention (also known as directed attention); and involuntary attention. Voluntary attention is the form of attention employed in attending to tasks or situations that require sustained attention and are not inherently easy to attend to. After prolonged and intense use, voluntary attention becomes fatigued.
In contrast, involuntary attention is said to be easy and does not require effort -- think of settings or activities in which remaining focused and attentive seems to happen naturally, without any deliberate effort. In Attention Restoration Theory, it is proposed that natural environments assist in recovery from directed attention fatigue, in part because they draw on involuntary attention rather than directed attention. These ideas led the researchers to propose that attention deficit symptoms would be more manageable after activities in green settings than after activities in other settings.
Participants in this study were parents of 96 seven- to twelve-year-old children diagnosed with ADHD (approximately 75% boys) who volunteered to complete a survey related to their childs activities and play settings. In the first section of the questionnaire, parents were asked to identify up to two after-school and weekend activities after which they felt their child functioned especially well (After ________ my childs ADD symptoms are much less noticeable than usual) and up to two activities they felt left their child functioning especially poorly (After ________ my childs ADD symptoms are much more noticeable than usual). Approximately two-thirds of the parents were able to identify at least one activity that they believed diminished or enhanced their childs inattentive symptoms.
Next, parents were presented a list of different after-school and weekend activities and asked to rate each activity in terms of its effect on their childs attentional functioning. These ratings were made on a 1 (more worse) to 5 (much better) scales. A rating of 3 was neutral and indicated that parents did not feel their childs attention problems were noticeably different after participating in the activity. Twenty-five activities were rated: 11 indoor activities, 6 outdoor activities in man-made settings, and 8 activities conducted in green outdoor spaces.
To examine whether childrens ADHD symptoms -- specifically problems with attention -- are diminished after activities in green settings, the authors compared activities that parents believed were associated with subsequent increases or decreases in their childs symptoms. Of the 20 activities judged by independent raters as unequivocally occurring in natural settings (e.g. playing in the woods), 17 (i.e. 85%) were nominated as best activities, meaning that after participating in these activities, parents felt their childs symptoms were noticeably diminished. Only 3 of these activities (i.e. 15%) were felt to be associated with a subsequent increase in ADHD symptoms. In contrast, of the activities nominated as worst (i.e. symptoms are worse immediately after these activities), 57% were activities that were likely to occur indoors or in man-made outdoor settings. Thus, green activities were significantly more likely to be nominated as best than not green activities.
The authors also examined parents ratings of their childs ADHD symptoms after participating in a wide range of activities that occurred in both natural and non-natural settings. They reasoned that if nature is supportive of childrens attentional functioning, activities conducted in green outdoor settings should receive higher ratings than activities conducted in indoor settings or man-made outdoor settings. Results were consistent with the hypothesized pattern as green activities received higher ratings (i.e. average rating of 3.54 on a 1 to 5 scale) than activities occurring in the other two contexts (i.e. 3.22 for indoor activities and 3.24 for activities in man-made outdoor settings). These differences were statistically significant.
To be more certain that these support an association between green activities and enhanced attentional functioning, the authors considered a number of alternative possibilities. For example, one alternative explanation for these results is that green activities enhance attentional functioning not because they occur in natural settings, but simply because they occur outdoors. If this were the case, however, then parent ratings of green activities and outdoor activities in man-made settings should not differ. As discussed above, however, green activities were rated more positively than other outdoor activities. (Remember, higher ratings indicate that parents felt their childs symptoms were better after participating in the activity.)
They also considered whether green activities may help diminish ADHD symptoms not because they occur in natural settings, but rather because they are more likely to involve physical activity. Active green activities (e.g. playing in a tree house) did not receive higher ratings than passive green activities (e.g. reading a book in a park). Thus, they did not find evidence that participating in green activities and better attentional functioning are associated because of the physical activity involved.
The authors also considered whether green activities are qualitatively different from activities that occur in non-green settings, and that this could explain their results. To examine this, they identified activities that were similar across the three settings and considered whether parent ratings still differed. Even for similar types of activities, parents still rated those occurring in green settings as more likely to be associated with a subsequent reduction in ADHD symptoms.
Finally, they considered whether activities in green settings may be associated with better attentional functioning simply because they are more likely to be preferred activities. According to parents ratings of their childs preferences, however, this did not seem to be the case. Many activities that were reported to be strongly preferred by children (e.g. watching TV and playing video games) were regarded by parents as leading to an increase, rather than a decrease, in their childs symptoms.
SUMMARY AND IMPLICATIONS
Results from this interesting study are consistent with the authors primary hypothesis that spending time in natural settings enhances the attentional functioning of children with ADHD. Based on these findings, the authors suggest that increasing the amount of time spent in green settings, particularly before times when sustained attention to tasks such as homework will be required, may offer a helpful addition to traditional treatments.
Although the authors are to be commended for their efforts to begin researching this interesting hypothesis, it is important to recognize that limitations in this study prevent any firm conclusions. One important limitation they acknowledge is that the design of their study was correlational, meaning that time spent in green settings was shown to be related to better attentional functioning. Correlational data, however, cannot establish causal relationships. This remains true despite efforts made by the authors to rule out alternative explanations of their findings. Evidence of causation can only be established by experimental studies.
Thus, the next step in this program of research would be an experiment in which children were randomly assigned to spend time in green and non-green activities, and then be measured on their subsequent functioning on tasks demanding sustained attention (e.g. schoolwork) by individuals who were not aware of what activity the child had just completed.
If it were found that childrens attention to these activities was significantly better after time spent in green vs. non-green settings, then more direct support for the benefits to attention of spending time in green settings would be provided. In the absence of this experimental evidence, no firm conclusions about the role of nature in enhancing attentional functioning can be drawn. (For example, it is possible the current results could be explained by the fact that parents believe that spending time in natural settings is good for children, and thus believe that children do better after contact with nature even though this is not objectively true.)
It is important to emphasize that highlighting this need for additional experimental research is not a criticism of the interesting work the authors have presented. The study they conducted is a reasonable first step in trying to establish a relationship between time spent in natural settings and diminished ADHD symptoms. It is, however, only a first step and should be clearly recognized as such.
Until more definitive evidence in support or refutation of their hypothesis is available, this work highlights the possibility that some activities -- whether they are green activities or not -- may be reliably associated with a subsequent reduction in childrens ADHD symptoms. It could be profitable, perhaps, for parents to think about how their child appears after engaging in different activities, and whether there are particular activities after which attentional functioning seems to improve. Trying to identify what these activities have in common, and working to incorporate any common features into a larger part of their childs day, would seem unlikely to cause any harm and might turn out to be quite helpful.