Meditation may calm the mind, but a recent study suggests it can also reshape brain activity by profoundly altering brain dynamics and increasing neural connections.
As a result, meditation may help practitioners achieve a state known as brain criticality, in which neural connections are at an optimal level for mental agility and function.
In the study, led by neurophysiologist Annalisa Pascarella of the Italian National Research Council, researchers used high resolution brain scans and machine learning to examine how meditation can alter brain activity to achieve an equilibrium between neural chaos and order.
First, the researchers used magnetoencephalography (MEG) to measure brain activity associated with two types of meditation and non-meditative rest in a group of 12 monks. MEG measures the magnetic fields produced by electrical signals in the brain.
The monks were professional meditators, averaging more than 15,000 hours of meditation each, from the Santacittarama monastery near Rome. All male and aged 25-58 years, the monks belong to the Thai Forest tradition, a branch of Theravada Buddhism known as the Way of the Elders because it’s grounded in the oldest Buddhist scriptures.
The study looked at two meditation techniques: Samatha, which centres the attention on a specific object, like mindful breathing, to achieve equanimity of mind, and Vipassana, which focuses the mind on the present moment so that sensations, emotions, and thoughts can flow freely without selective judgement.
“With Samatha, you narrow your field of attention, somewhat like narrowing the beam of a flashlight. With Vipassana, on the contrary, you widen the beam,” explains University of Montreal neuroscientist Karim Jerbi, senior author of the study.
“These two practices actively engage attentional mechanisms, attentional mechanisms, Jerbi adds, “and meditation practitioners often alternate between the two.”
Analysing the monks’ brain signals, the team found that while Samatha produced a more focused, stable brain state conducive to deep concentration, Vipassana got the monks closer to achieving brain criticality – a term borrowed from statistical physics and used over the past two decades to describe an optimal balance between chaos and order in neural functioning.
In this ‘sweet spot’ of efficiency, the brain becomes ideally attentive and flexible to effectively store and process information and swiftly adapt to changing tasks.
“At the critical point, neural networks are stable enough to transmit information reliably, yet flexible enough to adjust quickly to new situations,” says Jerbi.
“This balance optimises the brain’s processing, learning and response capabilities.”
Other differences also manifested. For example, Samatha may be more effective at activating sensory networks, enabling practitioners to better focus on a particular sensation, such as their breathing.
The new findings suggest meditation may promote a shift away from engagement toward awareness.
Among the 12 monks, more experienced meditators displayed a smaller difference between meditative and rest modes, suggesting their meditative brain states have become similar to their resting brain dynamics.
This research has been published in Neuroscience of Consciousness.
SOURCE: Science Alert
