Meditation, Cortical Thickness, and Pain Sensitivity

There’s a small but growing body of research literature showing that meditation practice is associated with greater cortical thickness in the brain (i.e., Grant et al., 2010; Lazar et al., 2005; Pagnoni & Cekic, 2007). All three studies used MRI scans to examine brain structures. In Lazar et al. (2005), a group of Insight meditation practitioners, regions of the brain associated with attention and sensory processing exhibited an increased thickness compared to a control group matched for gender, age, race, and years of education. Interestingly, the average thickness in the prefrontal cortex in 40-50 year-old meditators was similar to the average thickness of 20-30 year-old meditators and controls. This suggests that practice may slow age-related degeneration of brain tissue. Pagnoni & Cekic found a similar pattern in Zen practitioners.

More recently, Grant et al. (2010) examined the relationship between cortical structures and pain sensitivity in meditators. The researcher first compiled a list of 68 meditators willing to participate. In order to have a more homogenous sample, they chose Zen practitioners, who both made up the largest tradition in the list and reported more than 1,000 hours of meditation experience. Of the 19 Zen practitioners, 17 participated; these were matched against 17 non-meditators for age and gender.

A computer controlled increase in temperature, which was designed to create a moderate level of pain, was applied to the inner left calf of each participant. Cortical size was measured using MRI scans.

Zen practitioner exhibited lower pain sensitivity than controls. On average, Zen practitioners required an increase to 50°C in order to report a moderate level of pain; controls required an average of 48°C. Lower pain sensitivity was also related to greater cortical thickness, particularly in the dorsal anterior cingulated cortex, right anterior insula, and bilateral hippocampal formation. Greater thickness in these areas was related to greater meditation experience. Because this was a cross-sectional study and not a true experiment, we can’t be certain that there is a causal relationships between meditation experience, cortical thickness, and pain sensitivity. Taken together, the authors suggest that long-term meditation practice may lead to changes in the brain structures, which in turn may lower sensitivity to physical pain. The full article can be read in the most recent edition of the scientific journal Emotion. Interview excerpts with the first author about this study can be found at Science Daily.

A PDF of the Lazar et al. (2005) article can be found at the first author’s website.

The citations for the articles are:

Grant J.A., Courtemanche J., Duerden, E.G. Duncan G.H., & Rainville, P. (2010). Cortical thickness and pain sensitivity in zen meditators. Emotion, 10(1), 43-53.

Lazar, S. W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Treadway, M. T., et al. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport, 16(17), 1893-1997.

Pagnoni, G., & Cekic, M. (2007). Age effects on gray matter volume and attentional performance in Zen meditation. Neurobiology of Aging, 28(10), 1623-1627.

Hey, Is That Me over There?: Scientific American

Buddhism, as well as other world religions hold that a separate self is illusory. Yet our normal experience seems to be one of separation, that we experience the world from a stable location and are separate from others. However, both scientific work in psychology and neuroscience is beginning to show how "self" is a fully constructed phenomenon. Scientific American recently published an interesting article describing several studies that show how the sense of self can be manipulated through various procedures, thereby demonstrating its malleability. Here's a excerpt from the article:

If there is anything about your “self” of which you can be sure, it is that it is anchored in your own body and yours alone. The person you experience as “you” is here and now and nowhere else.
But even this axiomatic foundation of your existence can be called into question under certain circumstances. Your sense of inhabiting your body, it turns out, is just as tenuous an internal construct as any of your other perceptions—and just as vulnerable to illusion and distortion. Even your sense of “owning” your own arm is not fundamentally different—in evolutionary and neurological terms—from owning your car (if you are Californian) or your shotgun (if you are Sarah Palin). Outlandish as such a notion may seem, what you think of as your self is not the monolithic entity that you—and it—believe it to be. In fact, it is possible to pharmacologically manipulate body ownership.

Metacognitive Therapy for ADHD

Also in ADHD news: Medscape Today posted an article about a 12-week social skills group intervention that exhibited reductions in inattention in a sample of adults with attention deficit/hyperactivity disorder (ADHD). The treatment was metacognitive therapy, a newer cognitive behavior treatment that helps people recognize maladaptive patterns of rumination and worry. In metacognitive therapy, clients are taught what is called "detached mindfulness" in order to them move towards a decentered relationship with their thoughts and respond to experiences with greater attentional flexibility. Detached mindfulness facilitates greater flexibility in relating to thoughts, emotions, and beliefs. In the study, the experimental group was matched for medication use to a control group that received supportive therapy. This study offers strong support for the use of a mindfulness-based intervention for ADHD.

You can read the full story here if you're signed into Medscape. If you're not signed in, you can still access the story if you Google the key terms and click on the link from a Google page. Other online publications such as Science Daily have also run it, but I think the Medscape posting is a little more precise.

Mindfulness Meditation as a Potential Treatment for ADHD

Sharpbrains.com posted a summary of a really cool pilot study out of Duke University looking at the use of mindfulness meditation as an intervention for ADHD in adolescents and adults. Results suggest that the participants: 1.) Liked the intervention; 2.) Endorsed additional improvements in ADHD symptoms, even among those being treated with medication; 3.) Showed improvement on neuropsychological measures such as working memory and ability to shift attention; 4.) Exhibited reductions in anxiety and depression.

Although it’s too soon to call mindfulness meditation a stand-alone treatment for ADHD, this study provides some compelling data that it may be a useful complement to those with ADHD being treated with medication, particularly among those who may not respond as well to medication.

Read the full posting here:

http://www.sharpbrains.com/blog/2008/05/22/mindfulness-meditation-for-adults-teens-with-adhd/