Happy New Year! Let’s kick off 2023’s newsletters with a review of a classic paper led by neurotheology pioneer Andrew Newberg, who’s spent decades charting the intersection between religion and the brain.
Newberg, whose books include How Enlightenment Changes Your Brain (2016), and his team were the first to assess the same individuals doing different kinds of meditation, the first to examine the after-effects of meditation, and the first to evaluate feelings of connectedness in a brain-imaging study.
The 2011 paper in Psychiatry Research: Neuroimaging recruited 10 experienced meditators in Yogi Bhajan’s Kundalini yoga school – each had practised for over 30 years (estimated at 20,000 hours, or a very solid two hours per day).
Since then, Bhajan’s reputation has been hit with multiple credible and very unsavoury allegations, but the results from the paper stand on their own.
They were given a focus-based meditation, kirtan kriya (KK) – which I could swear I’ve written about for The Witness Space, but can I find it? – and a breath-based one, shabad kriya (SK). Both involve repeating the words “Sa, ta, na, ma”, after the Gumurki word “satnam” that’s often translated as “Truth is my identity”.
In KK, the mantra is spoken while the thumb and fingers are connected in sequence – first out loud for a few minutes, then whispered, then silently, whispered again and out loud; this takes some focus. In SK, the words match four deep inhalations and then four deep exhalations of the same duration, and has a more relaxing effect.
A control group counted to four while touching their thumb and fingers, though not in sequence.
The researchers set out with four goals:
Were different cerebral blood flow (CBF) changes associated with KK and SK for the same individual?
Were there correlations between CBF and subjective depth of practice?
Would meditation affect CBF variations in specific brain regions, counteracting stress?
Would there be persistent after-effects?
Spoiler alert: all four were found to be true, which is probably less of a good guess than Newberg et al having a good idea what they were going to find.
In KK (meditation 1 in the figures) compared to the controls, there was significantly increased CBF in the medial prefrontal cortex, associated with focus. In SK (meditation 2), though, significant activation took place in the limbic system, linked to the emotional effects of meditation – SK was also reported as more intense than KK by the trial subjects.
Both KK and SK saw decreased activity in the parietal lobes, though different again for each one. These areas are associated with the reported sense of altered space during meditation.
There were also strong correlations between meditation intensity and neural activity in the left inferior forebrain areas. Here, CBF increase was linked with lower perceived stress, suggesting a pathway for meditation to enhance positive emotions.
Finally, the data showed persistent changes in two areas of the brain. “The nature of these findings remains to be determined,” the authors write, adding, “We noticed that the persistent insular activation extended into the left frontal regions that have been implicated with positive emotions.”
Possible drawback No. 1: only 10 subjects, all of whom were experienced. Would meditation novices generate a different CBF pattern?
No. 2: Anything subjective is hard to measure accurately.
No. 3: Not varying the order of meditation (KK was always first) is a possible confounder. Everyone reported difficulty with the focus needed for KK while inside the bad-techno-music-hell of the MRI scanner. It’s possible the greater intensity reported for SK came as a result of progressive meditation.
No. 4: It’s possible that the breathing component of SK on its own made up part or all of the changes.
Bonus clip
Bonus bonus clip
Next week: neural correlates of non-dual awareness.