What is the best approach to use, yoga or meditation, if one wants to enhance/maintain their "fluid intelligence" and brain functional organization as one ages?
Jeff Walker, the heavily-engaged, co-financier of the research and initiatives in the Yale long-term meditator work ("Folk who meditate decrease mind wandering"), in which i was subject and collaborator, forwarded a recent study in "Frontiers of Aging Neuroscience" entitled "Fluid intelligence and brain functional organization in aging yoga and meditation practitioners" by Gard, et al.
Gard and 9 other researchers, including the highly-regarded Sarah Lazar, from Massachusetts General Hospital of Harvard (5), MIT, Stanford, Michigan State, Maastricht (Netherlands), Giessen (Germany), BrainBot (San Francisco) and Louvain (Belgium) (joint appointments) looked at this issue in a new, creative and useful way with much sophisticated data handling.
It has been broadly studied and documented that there is a "normal" age-related decline in brain functionality and cognitive performance and even the neural structure itself. There have been many control-based studies that indicated that meditation, as well as aerobic exercise, could slow this degradation.
Older meditators have been shown to beat similar-aged folk in a blink test measuring attention. Zen meditators did not show the typical drop in attention, short-term memory, perceptual speed and executive functioning with aging. Even the typical decrease in neural gray-matter volume with aging did not occur in meditation practitioners. (Refs in paper.)
The critique of these studies is that although the controls were matched for sex, age and education, they did not control for exercise and cognitive engagement, nor did they focus on higher level functioning such as "fluid intelligence", the capacity to think logically and solve problems in novel situations by identifying patterns and relationships that underlay these problems.
There is also much evidence that yoga can enhance cognition and brain function in younger adults, but there is less conclusive evidence on its effects in older folk. As there are many different yoga and meditation disciplines, and highly variable levels of dedication, clear resolution of effects and comparisons between and w/in the disciplines is difficult.
This study looked at 47 folk; 16 yoga practitioners, 16 meditation practitioners, and 15 carefully-matched, inexperienced controls. Meditators, with an average age of 54, were all trained in insight meditation/Vipassana/"mindfulness" (Goldstein and Kornfield, 2001) and had an average of about 7,500 hours of practice w/a standard deviation of 5,700 hrs (big variation). Yoga folk, w/an average age of 49, were trained in Kripalu Yoga and had an average of about 13,500 hrs of experience w/a standard deviation of about 10,000 hrs (big variation).
The study employed graph theoretical analysis, a "hot" area now in modeling the complexity of brain functional connectivity, to assess the effects of aging on network integration and fluid intelligence as well as "resilience" or the brain's ability to respond to damage from brain lesions and neuronal death.
The results on age vs fluid intelligence are at left. Both yogis and meditators showed much less decline in fluid intelligence with age than did the controls - the yogis appearing to do better than the meditators. However, due to the large data spread, while the difference from controls was significant, the difference between yogis and meditators was not statistically significant. (Would have liked to have seen an "hours of practice" graph which is very different from age.)
Changes in "brain architecture" were determined w/graph theoretical analysis, through measuring "small worldness", path length, and global efficiency. "Small worldness" is basically the linkage of strangers (or brain regions) through mutual acquaintances. The famous "Six Degrees of Kevin Bacon" posits that anyone on the planet can be related to Kevin Bacon through six or fewer acquaintance links. (i would have picked someone else.)
Graph theoretical analysis was done by dividing the brain into 116 regions and then computing the relationships between those regions for the three groups; meditators, yoga practitioners, and controls. The visualization of the network functional relationships for the meditators is shown below.
The thickness of the lines represents the strength of the correlation relative to the strongest correlation. Weaker correlations are not shown.
While this visual information is fascinating, it is difficult to process comparatively, so the characteristic path length, small worldness, and other parameters were compared separately.
The small-worldness chart at the right shows significant differences between the three populations. Yoga practitioners and meditators, separately and together, were significantly better in small-worldness than controls. There was no significant difference between the yoga practitioners and the meditators.
Similarly with "characteristic path length". Yoga practitioners and meditators, separately and together, had significantly shorter/better path length than controls, but were not significantly different from each other.
Resilience of the brains' functional networks to targeted, simulated, aging-related, brain damage revealed a similar pattern. Yoga practitioners and meditators together had a significantly smaller decrease in global efficiency than in controls (good). Separately, yoga practitioners showed a significant improvement while meditators showed no significant improvement over controls.
Interestingly, there was a separate metric for "mindfulness" based on the Five Facet Mindfulness Questionnaire or FFMQ of Baer et al.
These results at the right demonstrated that more mindfulness means higher fluid intelligence. It also produces better resilience and shorter characteristic path lengths (good). This agrees w/many other studies.
While there was high correlation in this study between Kripalu yogis and mindfulness meditators, other comparison studies of yogis with meditators have reported "both convergent and divergent findings", undoubtedly due to the wide variation in different practices. It is also important to note that the yogis in this study had almost 2X as many hours of practice as the meditators and were 5 years younger.
In the interest of full disclosure, this study was funded in part by the Kripalu Institute for Extraordinary Living and Jeff Walker. Also, the first of my yoga teachers' trainings was @ Kripalu a long, long time ago.
Obviously "mindfulness" meditation employs "mindfulness"; perhaps surprisingly, Kripalu yoga does as well, under the aegis of "witness consciousness". The Kripalu yoga that i learned was spontaneous posture flows coordinated with breath awareness and was certainly "meditative". Folk i sent to Kripalu for teachers' training reported that it has, not surprisingly, changed. Given this study's participants' ages and duration of practice, this is an additional complexity.
Even "yoga" is "complicated". i trained in several yogic disciplines. In most, "mindfulness" never entered the room, or even knocked at the door. Generalizing the results of this study to all yoga practices is not likely to be successful.
A very useful, carefully controlled study showing fairly convincingly that mindfulness meditation and at least one type of yoga had very beneficial effects on the retention of key elements of brain functioning as one ages, as measured by well-selected and skillfully-handled metrics. It begs a larger sampling to validate this important finding for all of us, those aged and those soon to become so.
BTW, Robert Wright ("How God(s) Evolve...Evidence of God?") has included our interview from Bloggingheads.tv in his Princeton University coursera course "Buddhism and Modern Psychology". That segment was watched by 14,000 folks.
Jeff Walker, the heavily-engaged, co-financier of the research and initiatives in the Yale long-term meditator work ("Folk who meditate decrease mind wandering"), in which i was subject and collaborator, forwarded a recent study in "Frontiers of Aging Neuroscience" entitled "Fluid intelligence and brain functional organization in aging yoga and meditation practitioners" by Gard, et al.
 |
| Tim Gard Harvard |
Gard and 9 other researchers, including the highly-regarded Sarah Lazar, from Massachusetts General Hospital of Harvard (5), MIT, Stanford, Michigan State, Maastricht (Netherlands), Giessen (Germany), BrainBot (San Francisco) and Louvain (Belgium) (joint appointments) looked at this issue in a new, creative and useful way with much sophisticated data handling.
It has been broadly studied and documented that there is a "normal" age-related decline in brain functionality and cognitive performance and even the neural structure itself. There have been many control-based studies that indicated that meditation, as well as aerobic exercise, could slow this degradation.
Older meditators have been shown to beat similar-aged folk in a blink test measuring attention. Zen meditators did not show the typical drop in attention, short-term memory, perceptual speed and executive functioning with aging. Even the typical decrease in neural gray-matter volume with aging did not occur in meditation practitioners. (Refs in paper.)
 |
| Jeff Walker |
The critique of these studies is that although the controls were matched for sex, age and education, they did not control for exercise and cognitive engagement, nor did they focus on higher level functioning such as "fluid intelligence", the capacity to think logically and solve problems in novel situations by identifying patterns and relationships that underlay these problems.
There is also much evidence that yoga can enhance cognition and brain function in younger adults, but there is less conclusive evidence on its effects in older folk. As there are many different yoga and meditation disciplines, and highly variable levels of dedication, clear resolution of effects and comparisons between and w/in the disciplines is difficult.
This study looked at 47 folk; 16 yoga practitioners, 16 meditation practitioners, and 15 carefully-matched, inexperienced controls. Meditators, with an average age of 54, were all trained in insight meditation/Vipassana/"mindfulness" (Goldstein and Kornfield, 2001) and had an average of about 7,500 hours of practice w/a standard deviation of 5,700 hrs (big variation). Yoga folk, w/an average age of 49, were trained in Kripalu Yoga and had an average of about 13,500 hrs of experience w/a standard deviation of about 10,000 hrs (big variation).
The study employed graph theoretical analysis, a "hot" area now in modeling the complexity of brain functional connectivity, to assess the effects of aging on network integration and fluid intelligence as well as "resilience" or the brain's ability to respond to damage from brain lesions and neuronal death.
 |
| Kevin Bacon |
Graph theoretical analysis was done by dividing the brain into 116 regions and then computing the relationships between those regions for the three groups; meditators, yoga practitioners, and controls. The visualization of the network functional relationships for the meditators is shown below.
 |
| Resting-state brain region functional relationships for meditators |
The thickness of the lines represents the strength of the correlation relative to the strongest correlation. Weaker correlations are not shown.
While this visual information is fascinating, it is difficult to process comparatively, so the characteristic path length, small worldness, and other parameters were compared separately.
 |
| Small-worldness |
 |
| Characteristic path length |
Resilience of the brains' functional networks to targeted, simulated, aging-related, brain damage revealed a similar pattern. Yoga practitioners and meditators together had a significantly smaller decrease in global efficiency than in controls (good). Separately, yoga practitioners showed a significant improvement while meditators showed no significant improvement over controls.
Interestingly, there was a separate metric for "mindfulness" based on the Five Facet Mindfulness Questionnaire or FFMQ of Baer et al.
These results at the right demonstrated that more mindfulness means higher fluid intelligence. It also produces better resilience and shorter characteristic path lengths (good). This agrees w/many other studies.
While there was high correlation in this study between Kripalu yogis and mindfulness meditators, other comparison studies of yogis with meditators have reported "both convergent and divergent findings", undoubtedly due to the wide variation in different practices. It is also important to note that the yogis in this study had almost 2X as many hours of practice as the meditators and were 5 years younger.
In the interest of full disclosure, this study was funded in part by the Kripalu Institute for Extraordinary Living and Jeff Walker. Also, the first of my yoga teachers' trainings was @ Kripalu a long, long time ago.
 |
| Sarah Lazar (center) in her lab @ Harvard |
Obviously "mindfulness" meditation employs "mindfulness"; perhaps surprisingly, Kripalu yoga does as well, under the aegis of "witness consciousness". The Kripalu yoga that i learned was spontaneous posture flows coordinated with breath awareness and was certainly "meditative". Folk i sent to Kripalu for teachers' training reported that it has, not surprisingly, changed. Given this study's participants' ages and duration of practice, this is an additional complexity.
Even "yoga" is "complicated". i trained in several yogic disciplines. In most, "mindfulness" never entered the room, or even knocked at the door. Generalizing the results of this study to all yoga practices is not likely to be successful.
A very useful, carefully controlled study showing fairly convincingly that mindfulness meditation and at least one type of yoga had very beneficial effects on the retention of key elements of brain functioning as one ages, as measured by well-selected and skillfully-handled metrics. It begs a larger sampling to validate this important finding for all of us, those aged and those soon to become so.
BTW, Robert Wright ("How God(s) Evolve...Evidence of God?") has included our interview from Bloggingheads.tv in his Princeton University coursera course "Buddhism and Modern Psychology". That segment was watched by 14,000 folks.
and now if we can get some longitudinal studies going with larger sample populations .. that would be something :)
ReplyDeleteHi Jeff,
DeleteYes, hopefully the work will attract the attention it deserves. With a large Baby Boomer demographic aging into those years, it will be an issue that should attract major agency funding, both from quality-of-life and health care cost perspectives. Much gratitude to you for your insightful and engaged funding of this, and of course, for the Yale long-term meditator work.
stillness
gary