Meditation affects people in different ways

A group of researchers from the HSE Centre for Bioelectric Interfaces has studied the activity of the brain and other body systems during meditation. It was the first study to show that, when following the same instructions, some people relax, while others concentrate. The results of the study were published in the PLOS ONE journal.

Meditation has become increasingly popular in the western world in recent decades, which led to the increase in the number of studies dedicated to the impact of meditation on the human body. It has already been demonstrated that regular meditation sessions positively affect a person's psychological state, slow down the development of age-related cognitive disorders, reduce stress and systemic inflammation.

Some modern gadgets promise to increase the effectiveness of meditative practice by providing biofeedback based on the analysis of physiological indicators of the meditator. There are already several devices available on the market that implement this function and are highly regarded by consumers. But so far, such products offer general feedback algorithms for all users—not ones adapted to a specific person. Scientists still do not understand the processes behind meditation, nor how they differ from one person to another.

Researchers from the HSE Centre for Bioelectric Interfaces—with the support of instructors from the ‘Our School’ (‘Svoya Shkola’) school of healthy movement—studied the change in human physiological indicators during meditation. The experiment involved two groups of participants (28 people): one group of people who have been practicing meditation regularly for two years or more (for an average of 8 years), and those without such an experience. All the participants performed the same meditation by following audio instructions for 37 minutes. The instruction included 16 separate parts specifically adapted for the purposes of this study.

Maria Volodina, the first author of the study and Junior Research Fellow at the HSE Centre for Bioelectric Interfaces:

‘It was important that we planned the experiment in a way that linked the registered physiological indicators to specific parts of the meditation. The majority of existing studies just compare meditation and resting state, but they do not analyze how physiological indicators change during immersion into and out of the meditative state.’

According to the researchers, in order to create an interface for assisted meditation, it is important to understand not only the state that a person wants to achieve, but also the path through which they can be ‘guided’ into this state. To solve this problem, the researchers worked with experienced instructors of meditative practices to adapt the existing instruction by dividing it into separate parts. After a short audio instruction, there was a two-minute pause during which the subject was supposed to act accordingly. The researchers recorded the participants' brain activity (EEG), respiratory rate, heart rate, and galvanic skin response.

This data allowed them to assess how the indicators changed during the process of entering and exiting a meditative state. The researchers expected experienced meditators to exhibit changes in their physiological indicators typical of a state of relaxed awareness: simultaneous mental concentration and body relaxation.

However, the results did not confirm this hypothesis. Unexpectedly, the group of experienced practitioners split into two distinct groups. In half of the experienced participants, changes in brain activity were observed during meditation (in particular, a decrease in alpha rhythm was observed), indicating mental concentration. The changes became most noticeable in the midst of the meditation. By the end, the indicators had returned to their original values. Markers of relaxation at the body level (breathing and heart rate variability) did not change significantly throughout the experiment.

The second group of the experienced practitioners showed signs of body relaxation throughout the meditation: slow breathing and increase in the heart rate variability. The alpha rhythm power greatly increased during the final stages of the meditation and after the end of it, which indicated mental relaxation.

The results displayed by the control group (people without meditation experience) fell roughly in between those of the two groups of the experienced meditators. They did not demonstrate any significant changes either in the indicators of bodily relaxation or those of mental concentration.

‘We have several hypotheses that could explain the results. We have already started the necessary experiments to test them. One possible explanation is that every person has an innate predisposition to one or another physiological strategy of immersion in the meditative state. If this hypothesis is true, the use of standardized devices for teaching meditation based on biofeedback may not only be ineffective in achieving the desired result, but could actually be harmful to some users. The question of whether one of the strategies may be preferable for the long-term positive effects of meditation still needs to be studied,’ explains Maria Volodina.