by Carrie Heeter, PhD, May 25, 2017
As a student, practitioner, designer, and researcher of meditation, I am interested in scientific findings about meditation and the curious methods scientists use to arrive at those findings.
In this blog I write about a recent neuroimaging (fMRI) brain scan study of the relationships between mind-wandering and focused attention meditation.
A different team of neuroscientists explored underlying neural circuitry of two distinct forms of meditation — Focused Attention (FA) meditation, on a specific, chosen object versus Open Monitoring (OM) meditation, where attention focuses on the experience from moment to moment. (Lutz et al., 2008).
Scheibner and colleagues (2017) wondered whether Focused Attention meditation when the object of attention was internal (in this study, breath) had the same or different effects on mind-wandering as when the object of attention was external (in this study, sound).
Mind-wandering (thinking about anything other than present moment experiences) is known as the Default Mode neural Network (DMN). Mind-wandering is what human minds tend to do in a resting state, and also throughout the rest of life. For the most part, ruminating about the past and worrying about the future are not beneficial to health, well-being, or happiness.
- Scheibner’s team found doing a focused attention meditation was associated with significant reductions in activity in the parts of the brain involved in DMN during the meditation.
- The difference was significant for both internal and external meditation objects.
- For one DMN brain region (the posterior cingulate cortex), there was stronger deactivation with internal meditation compared to external.
- In other research, posterior cingulate cortex deactivation was associated with subjective experiences of “undistracted awareness” and “effortless doing”. Thus, internal focused attention meditation resulted in more of this than did external focused attention meditation.
So, yay meditation! And yay internal meditation objects!
Let’s look at how they did the research.
20 “meditation-naive” adult participants were recruited.
Two Focused Attention meditations were planned. The internal meditation focused attention on breathing. The external meditation focused attention on sound. Specifically, on a repeating cycle of two violin notes — the first held for 2 seconds, the second held for three seconds, at “a major third” distance.
One internal meditation object (breath) and one external meditation (sound)
Experiments try to control for extraneous factors that might influence results in unknown yet systematic ways. So these researchers decided to ask the participants to play the audio loop of the repeating violin notes when they did the breath meditation as well as when they did the sound meditation. For the breath meditation, participants ignore the sound of the violin and instead pay attention to their breath. And for the sound meditation, they ignore their breath (not a specific instruction, I’m just drawing a parallel here) and pay attention to the violin sound.
The researchers note that the two-note violin loop “results in a cycle frequency of 0.2 Hz) which equates with breathing frequency at rest.”
It is easy to criticize the choices researchers make. But it is also reasonable to do so.
First, individuals have unique breath rates and breathing patterns. 0.2 Hz might be an average breath cycle, but almost certainly did not match many or even any of the 20 participants’ individual breath rates.
It strikes me that having a 0.2Hz rhythmic cycle of sound playing during a breath meditation would impact breath rate and also result in more of a mixed internal/external meditation where the breath and the rhythm of the sound intermingle as meditation object.
I happen to have a personal extreme dislike of the sound of a violin. So for me, both meditation experiences would have been highly agitating.
Brain Imaging Process
With brain imaging research, you want to know exactly what the brain is doing relative to the brain images you are recording. The researchers devised an interesting approach to achieve this goal. Participants were initially trained to do the two meditations. Then they practiced each meditation on their own at home for 20 minutes per day for 4 days. On day 6 they returned to the laboratory to do both meditations twice while their brain activity was recorded.
Specifically, they did either internal or external for 14 minutes, then switched to the other meditation for 14 minutes. Then they did either the internal or external meditation for 7 minutes. Then switched to the other meditation for 7 minutes. (Order was carefully randomized. The shorter duration of the second to meditations was to avoid fatigue.)
While they did the meditations in the laboratory their gaze was focused on a white cross on a computer screen. At pseudo-random intervals ranging from 2 to 50 seconds apart, the white cross turned to a red cross and participants answered the onscreen question: where was your mind? BREATH or DISTRACTED (or, for the violin, SOUND or DISTRACTED).
Based on the reply, the researchers classified the time right before question as either mind-wandering or focused. In this way they could analyze just the focused brain images.
This is quite ingenious.
28 interruptions during a 14 minute meditation also would have limited the depth of the experience. Eyes open waiting to be interrupted also impedes pure focus on the meditation object (compared to eyes closed).
The “meditation” experiences on which the research is based are very different from the meditation experiences that I practice and study. Do the results generalize to yoga meditations by experienced practitioners, with carefully sequenced movement and breathing and carefully chosen meditation objects?
This is the way research on meditation works. The process is much stranger than the results.
Lutz, A., Slagter, H. A., Dunne, J. D., & Davidson, R. J. (2008). Attention regulation and monitoring in meditation. Trends in Cognitive Sciences, 12(4), 163–169. https://doi.org/10.1016/j.tics.2008.01.005
Scheibner, H. J., Bogler, C., Gleich, T., Haynes, J.-D., & Bermpohl, F. (2017). Internal and external attention and the default mode network. NeuroImage, 148, 381–389. https://doi.org/10.1016/j.neuroimage.2017.01.044