Unscrambling how Hindu and Buddhist meditations affect the brain
Different actions, different networks?
One of the biggest kicks I get out of researching topics for The Witness Space is: how did they know?
How did the sages of three, four or five thousand years ago know that this set of particular actions in this particular order would produce the kind of effects that modern neuroscience – as hedged with caveats and correlations as is it – is suggesting?
Take the difference outcomes of Hindu and Buddhist meditation. Broadly put, the first has a goal of achieving non-dual awareness, the second of reaching mindfulness by sustained attention on what arises.
A 2014 paper in Brain and Cognition set out to examine the hypothesis that they’ll also activate different brain networks.
The Italian authors provide fascinating background on both types of meditation, opening with a discussion of Patanjali’s foundational Yoga Sutra. He declared that Yoga enables the “suppression of the fluctuations and modifications of the mind” via specific postures and breathing, focus and absorption in meditation leading to a loss of sense of self, or samadhi.
They list seven different types of Hindu-linked meditation. Relaxation or yoga nidra activates areas related to mental imaging – fitting, given that you’re focusing on different parts of the body.
Chanting mantra activates language areas and deactivates a region that controls spatial orientation. Silent meditation activates regions that allow for the awareness of bodily sensations and involvement in body positions, while shabad kriya, its aim to promote higher absorption, deactivates regions involved in stress response, attention regulation and feelings of connectedness.
Regarding Buddhism, they quote from the Buddha’s observation of how to reach samadhi in the Upasivamanavapucca: “Observing nothingness, being mindful [of it].”
And the authors detail the results of various neuro-imaging studies in linked practices. Long-term meditators in sustained attention activated the attention network and deactivated regions related to conceptual thought.
Loving-kindness meditators activated a network associated with processing mental states of others, while mindfulness breathing by Zen meditators deactivated a network involved with referencing the self.
The aim of their study – involving a meta analysis of functional magnetic resonance imaging (fMRI) – was to test a 2009 hypothesis proposing that Buddhist meditation would different from the Hindu varieties because of its focus on mindfulness.
Namely, there would be higher activation in areas relayed to exercising voluntary attention, paying attention and self-consciousness – all correlated with frontal lobe activation and based on what’s known as the cognitive domain.
The Hinduist tradition, on the other hand, with the goal of achieving a non-conceptual state of consciousness, would see activation in the pareto-temporal areas. This type is known as the null domain.
The authors scoured global databases for whole-brain group analyses, producing eight covering Hindu meditation and 18 for Buddhism. They acknowledge various limitations of the approach: there’s no standard definition of meditation, and studies cover different types of meditation at different stages and use subjects with different levels of experience.
Not only that, they had to transform the results from each paper into a standard 3-D grid of the brain to be able to compare them with each other.
And I’ll add my personal favourite, given there were only 66 and 263 subjects respectively.
All this being equal, though, they did discover consistent and different activation patterns, and next week we’ll discuss what they were.