One of the fun aspects about researching these posts is coming across spiritual practices I’ve not heard of – such as Raja yoga, the subject of an article in International Journal of Yoga.
The Indian study, led by a professor from the department of electronics and communication engineering at Bengaluru’s BNM Institute of Technology, used fMRI scans on short- and long-term meditators, and ran the results through five models designed to try and tell the two groups apart.
Does long-term meditation produce lasting changes in the brain?
But first, Raja yoga, which is part of the Brahma Kumaris tradition. Meditation is often performed with the eyes closed, to help concentration, but not in this case. The eyes remain open, making it “more useful in day-to-day life while doing mundane activities”, say the paper’s authors, though you probably shouldn’t be behind a wheel or operating heavy machinery. Or anything involving knives.
This link from the official website offers more detail on the five steps involved: relaxation, concentration on the thoughts you want to have, contemplation and self-reflection, realisation and, confusingly, meditation (again).
And here’s a handy clip (which is showing as a captcha in draft). A guided meditation starts at 9:40.
But what does repeated Raja yoga meditation do to the brain? The researchers recruited 12 long-term practitioners (LTP) with at least 10 years’ practice, ranging from 7300 to 35,040 hours. The short-term group (STP) of 10 had six months to two years of meditation, ranging from 274 to 2190 hours. They were between 27 and 65, and with diverse socioeconomic and educational backgrounds. No left-handers though!
The fMRI test protocol was rest, task, rest, with one of the rest blocks being meditation. The task, which “resembles a real-life scenario where there is a need for decision-making in the presence of multiple distractions” played out on a 40-inch monitor. The screen, headphones and buttons for participant responses were, you’ll be glad to hear, all MRI compatible.
Prior MRI studies – the authors could only find three concerning Raja yoga – found evidence for transient and longer lasting brain changes. Long-term meditators had higher connectivity (in medicalese, an increase in fractional anisotrophy values) and reduced mean diffusivity in the corpus callosum, which bridges the left and right sides of the brain.
Raja yoga meditators also had higher happiness scores and higher gray matter volumes in (deep breath) the inferior orbitofrontal gyrus, right superior frontal gyrus and bilateral precuneus, the latter of which could come in handy in a tight Scrabble hand. Grey matter volume was also greater in the bilateral ventral pallidum for the long-termers.
So, then: plenty of evidence suggesting “experience-dependent plasticity”.
Using a variety of machine learning models, including the hauntingly named Random Forest, the researchers found that one was able to distinguish between the LTP and the STP, knitting together data from 132 regions of interest.
Wouldn’t it be simpler to just ask someone how long they’ve been practising?
But as a Christmas treat, the researchers caution that there was a challenge to training their models.
The Witness Space is taking a festive break and will return on January 16, 2023. Merry Christmas and a Happy New Year!