Kamal Ghorui
BENGALURU: A new study from IISc suggests that long-term meditation may quietly reshape how the brain processes information, not just during meditation, but even at rest.Researchers tracked brain activity in people who had practised meditation for years and compared them with those who had never meditated. What they found was simple to state but striking in implication: meditators showed stronger brain signals linked to attention and perception.At the centre of the study is a type of brain activity known as “gamma waves”. These are electrical rhythms that appear when the brain is actively processing sensory information. For instance, when recognising visual patterns.The study found two key patterns. Even when doing nothing in particular, meditators had higher levels of these gamma signals. When shown visual patterns designed to trigger brain responses, their brains reacted more strongly than non-meditators, specifically in the slower end of the gamma range. In effect, their brains appeared more responsive both at rest and when stimulated.
What researchers did
The team recorded brain activity using EEG, a non-invasive method that tracks electrical signals through sensors placed on the scalp. They studied more than 70 adults, including long-term practitioners of Rajyoga meditation and a matched group with no meditation experience.Participants were asked to sit through a series of sessions: resting, looking at visual patterns, and meditating — sometimes with their eyes open, which is a feature of Rajyoga practice. This allowed the researchers to compare how the brain behaved across different conditions.The study was led by Ankan Biswas along with Srishty Aggarwal and Kanishka Sharma, under the guidance of Supratim Ray at IISc’s Centre for Neuroscience, with contributions from the Department of Physics and the IISc Mathematics Initiative. It has been published in Imaging Neuroscience.
What stood out
One of the clearest findings was consistency. Meditators showed stronger gamma activity not just during meditation, but before and after it as well.The study also found that two kinds of gamma signals, one triggered by external visuals and another generated internally during meditation, could exist at the same time without interfering with each other. These two signatures were prominent in different brain regions, suggesting they arise from different mechanisms.This suggests that meditation does not simply “quiet” the mind, as is often assumed. Instead, it may allow different brain processes to run in parallel more efficiently.Another marker the researchers looked at was the overall pattern of brain signals, which tends to flatten with age. In meditators, this pattern remained steeper, a sign often linked to healthier brain function.
Why it matters
The findings point to a possibility that meditation could help maintain the brain’s internal balance, particularly the fine interplay between excitation and inhibition that underlies clear thinking.Such balance is known to weaken with ageing and in conditions like Alzheimer’s disease. While the study does not claim meditation as a treatment, it raises the possibility that long-term practice may slow some of these changes.
