Confronting claims about mindfulness training changing the brain with claims that exposure to parks changes the brain suggests that neither claim had evidence.
“Although the practice of meditation is associated with a sense of peacefulness and physical relaxation, practitioners have long claimed that meditation also provides cognitive and psychological benefits that persist throughout the day,” says Sara Lazar, PhD, of the MGH Psychiatric Neuroimaging Research Program, the study’s senior author. “This study demonstrates that changes in brain structure may underlie some of these reported improvements and that people are not just feeling better because they are spending time relaxing.”
What was the evidence for these claims?
For the current study, MR images were taken of the brain structure of 16 study participants two weeks before and after they took part in the 8-week Mindfulness-Based Stress Reduction (MBSR) Program at the University of Massachusetts Center for Mindfulness. In addition to weekly meetings that included practice of mindfulness meditation — which focuses on nonjudgmental awareness of sensations, feelings and state of mind — participants received audio recordings for guided meditation practice and were asked to keep track of how much time they practiced each day. A set of MR brain images were also taken of a control group of non-meditators over a similar time interval.
How were these differences interpreted?
“It is fascinating to see the brain’s plasticity and that, by practicing meditation, we can play an active role in changing the brain and can increase our well-being and quality of life.” says Britta Hölzel, PhD, first author of the paper and a research fellow at MGH and Giessen University in Germany. “Other studies in different patient populations have shown that meditation can make significant improvements in a variety of symptoms, and we are now investigating the underlying mechanisms in the brain that facilitate this change.”
Amishi Jha, PhD, a University of Miami neuroscientist who investigates mindfulness-training’s effects on individuals in high-stress situations, says, “These results shed light on the mechanisms of action of mindfulness-based training. They demonstrate that the first-person experience of stress can not only be reduced with an 8-week mindfulness training program but that this experiential change corresponds with structural changes in the amygdala, a finding that opens doors to many possibilities for further research on MBSR’s potential to protect against stress-related disorders, such as post-traumatic stress disorder.” Jha was not one of the study investigators.
In general, it is not reasonable to make a big deal of a study comparing only 16 participants practicing mindfulness to 16 people who did not. Such a study is much too small to yield reliable, replicable differences. To be statistically significant in such a small study, differences between the two groups would have to be quite large. Mostly, large differences between groups found in small studies are exaggerated.
Even if moderate differences in grey matter were associated with an intervention, the likelihood of them being shown in such a small study is considerably less than 50%. Meaning? That these are most likelyspurious findings, even if real effects actually existed.
Even if such differences could be shown (and they were not reliably shown in this study, we wouldn’t know if anything specific about mindfulness caused them.
To make a fuss about these differences in terms of the function of these regions of the brain is silly.
Exhibit B: And now for the contrasting study.
Being surrounded by greenery was good for grey matter, as it was calming and quieter, according to the first study to look at the impact of parks on the mental health of pensioners.
Walking between busy urban environments and green spaces triggers changes in levels of excitement and engagement and reduces frustration.
The findings have important implications for architects, planners and health professionals with gardens and parks coming under pressure from austerity as we deal with an ageing population.
What was the evidence for these claims?
As part of the experiment, eight volunteers aged 65 and over from a wider sample of 95 wore an EEG (electroencephalogram) headset which recorded their brain activity as they walked.
The researchers also ran a video of the routes, asking the participants to describe ‘snapshots’ of how they felt. The volunteers were also interviewed before and after.
The study published in the International Journal of Environmental Research and Public Health found as well as preferring green space, it was beneficial to the volunteers’ brain health by being calming and quieter.
Co-author Dr Sara Tilley, of the University of Edinburgh, added: “To help ensure living longer is a positive experience for everyone, we need evidence based solutions to support lifelong health and well being.
Well, maybe, but this is not the kind of evidence that is needed. Numbers from such a small study are not evidence. But was the interpretation that was given?
“These findings – and others from the same project which show how important places are for our personal and cultural memories, and for enabling us to stay connected socially – have implications for the way we design for people of all ages, backgrounds and abilities so going outdoors in younger years becomes a lifelong passion for getting out and about.”
They mirror the findings of the 2013 study of younger adults from Heriot-Watt University, Edinburgh, which also found being surrounded by green reduced frustration and increased engagement.
Those researchers who also tracked brainwaves said parks affect the mind in a similar way to meditation.
I do not think either news item provides much evidence. We shouldn’t ignore the lack of sound evidence in comparing the two, but if we do, we have to say whatever is going on, is probably not very specific. But I doubt we have evidence that anything is going on that we did not have before these studies were introduced.
By the way, the parks-affect-the brain news item got more nonsensical if we had kept going:
A 2015 study of about 2,000 seven to 10 year old primary schoolchildren in Barcelona showed they improved memory and reduced inattentiveness in schools.
The findings may partly be explained by reduced exposure to traffic pollution, experts believe.
Other influences could include the psychological effect of having views of fields and trees rather than roads and buildings.
I will soon be offering e-books providing skeptical looks at mindfulness and positive psychology, as well as scientific writing courses on the web, as I have been doing face-to-face for almost a decade.
Sign up at my new website to get advance notice of the forthcoming e-books and web courses, as well as upcoming blog posts at this and other blog sites. Lots to see at CoyneoftheRealm.com.