Monday, January 14, 2013

Mindfulness neuroscience

The journal Social Cognitive and Affective Neuroscience has released an issue devoted to studies of brain correlates of different kinds of meditation. One article, on compassion or loving-kindness meditation, is open access. For me, the crucial article is the last one, written by a senior guru of the brain imaging field, Michael Posner, and his colleague Yi-Yuan Tang, outlining theoretical and methodological issues in the field. They note that reviews of the field have:
..summarized four components of how mindfulness meditation may work: (i) attention regulation, (ii) body awareness, (iii) emotion regulation (including reappraisal, exposure, extinction and reconsolidation) and (iv) change in perspective on the self. The authors indicate that mindfulness practice comprises a process of enhanced self-regulation that can be differentiated into distinct but interrelated components. While these components are a start, future empirical work should identify additional components of mindfulness and establish to what extent the components involve distinct mechanisms.
Many studies have difficulties with appropriate control and comparison subjects:
Different control and comparison groups have been used in mindfulness research, such as waiting lists, active control groups and interventions designed to match the non-specific effects of mindfulness practices, such as trainer’s confidence, expectancy effects and group support... Ideally, participants would be randomly assigned to condition, and the conditions would be matched with the many non-specific factors that have been found to produce beneficial change... Random assignment allows the changes observed in mindfulness research to be reasonably attributed to the active ingredient of mindfulness practice per se rather than to pre-existing differences in the experimental and control groups. Therefore, moving the field will require the use of rigorous comparison conditions to which participants are randomly assigned.
In long-term studies, an active control is not possible. In studies of long-term practitioners such as monks with many thousands of hours of practice, it is challenging to find even a matched control group. We don’t know how the monks differed before meditation practice and other factors including the environment and low stress, which differ from any ‘matched’ control group.
Other issues are that the various studies employ different mindfulness techniques, stages of practice, or duration of training. (Motivated readers can request a copy of his article from me.)

5 comments:

  1. Anonymous6:43 AM

    A touch ironic that Tang and Posner highlight the need for careful active control in a special issue of their curating, in which (by my count) only 2/14 included papers meet those criterion. Folks like Richard Davidson have been saying this for years and yet for the most part we don't see it happening. Each month we see more waitlisted, correlational, and cross-sectional research published in top journals but the randomized controlled studies (particularly in imaging) are few and far between. More worrisome are rumors that labs that have tried (Davidson group for example) careful active controls tend to find nothing more often than not. Without active controls we will never know which intervention elements actually work in a specific fashion and the literature becomes entirely self-fulfilling.

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  2. I really should have mentioned that Posner's critical comments were basically lifted from Davidson's earlier papers. And you are right, Richie Davidson's group has found that previous results can melt in properly controlled experiements.

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  3. Hi,

    I am a very assiduous reader of your blog. Thanks for keeping us updated on these sort of topics I really appreciate it.
    I was wondering if you could recommend any book on meditation (for beginners)? After reading so many of your entries about mindfulness I have decided to give it a try.

    Thanks you.
    Ivan Puga

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  4. I would suggest starting with the simple guides written by Kabat-Zinn, and he has a number of YouTube instructional videos... just enter Kabat-Zinn in YouTube, google, or amazon search boxes.

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