S21. Seeing How Meditation Clears Brain “Noise” Through EEG
- Jun 30
- 7 min read
Why are scientists so interested in “thoughtless” states?
Many people say meditation helps them feel calmer, clearer and even happier.But if we hook a meditator up to an EEG machine, what exactly happens inside the brain during meditation?
A research team in Russia used high‑resolution EEG (electroencephalography) to study Sahaja Yoga meditation. They did not just ask whether brain waves become “stronger.” They wanted to know something more subtle:
Can we actually measure, with scientific instruments, that meditation reduces “noise” in the brain and lets only the essential activity remain?
This study was designed to answer that question.
First things first: what is EEG, and is it scary?
EEG (electroencephalography) is a technique that records the brain’s electrical activity from electrodes placed on the scalp.
In more technical terms, EEG measures voltage changes produced by large groups of neurons firing together.
In everyday language, you can think of it as a “heart ECG,” but for the brain, showing the rhythms and strength of brain activity in different regions.
In this study, the participants wore a cap with 62 electrodes, closed their eyes, and did two things:
Simply rested with eyes closed.
Entered the Sahaja Yoga meditation state of mental silence, also called thoughtless awareness – a state where you are awake and aware, but free from unnecessary thoughts.
The researchers then selected clean EEG segments without artifacts like eye blinks or muscle noise and analyzed them.
S13 vs S21 in one sentence: one study looks at “what lights up,” the other at “how much noise is turned off”
Before this S21 paper, the same team had already published another study (S13), also using Sahaja Yoga meditation and EEG.If we compare the two in very simple terms:
What did S13 study?
It mainly looked at spectral power (how strong different brain wave bands are) and coherence (how synchronized different brain regions are).
The key question was: “During meditation, which brain waves increase, which regions become more synchronized, and how does this relate to emotion and attention?”
The conclusion: during meditation, theta and low alpha activity over frontal and midline regions increased, and this was linked to internalized attention, positive emotion, and fewer intrusive thoughts.
What does S21 (this paper) study?
It re‑analyzes the same EEG data from S13, but with a deeper method.
In addition to power, it adds a nonlinear measure called dimensional complexity (DCx).
The key question becomes: “During meditation, does the brain’s activity become more chaotic and complex, or does it actually become simpler and more orderly, with less noise?”
Analogy:
S13 is like looking at a stage to see which spotlights turn on and which lights blink together.
S21 is like asking “Is the whole lighting system still full of random flashes, or has it been simplified into a few well‑coordinated patterns for the performance?”
The star of S21 is this “complexity” measure – essentially, whether the brain’s internal noise really switches off.
Key terms: theta, alpha, and DCx in plain English
Brain wave bands: different rhythms, different roles
EEG can be decomposed into different frequency bands, each roughly associated with different mental functions:
Theta (about 4–8 Hz)
Often linked to internalized attention, emotional processing, memory, and certain meditative states.
Think of it as a slower, deeper rhythm that, in meditation, reflects deep but relaxed concentration.
Alpha (about 8–12 Hz)
Often divided into low alpha (alpha‑1) and faster alpha‑2.
Alpha‑1 is commonly associated with closing down external attention and shifting inward.
Alpha‑2 is more related to higher‑order cognitive processes and expectancy.
Beta (about 12–30 Hz)
Faster, often linked to active thinking and alertness.
In this paper, beta‑3 (22–30 Hz) is of special interest because of its relationship to complexity.
Dimensional Complexity (DCx): an indirect measure of “how noisy” the system is
Dimensional complexity (DCx) is a nonlinear measure used to estimate how many independent patterns of neural activity are running at the same time over a given period.
In technical terms, DCx is treated as an index of the complexity of neuronal computations: a higher value suggests more independent neural assemblies are active simultaneously.
In everyday language, imagine standing on a tall building at night looking over a city:
If there are cars moving in many directions on many different streets, the traffic pattern is highly complex.
If most small streets are empty and only a few main roads carry well‑organized traffic, the system is less complex.
This study asks: during meditation, does the brain look more like “traffic everywhere,” or like “a few main roads running smoothly”?
Mental Silence / Thoughtless Awareness: awake, clear, but without mental chatter
In the Sahaja Yoga framework, the core meditation state is not drowsiness or drifting off, but mental silence or thoughtless awareness:
You are fully awake and your senses are open.
But most unnecessary inner commentary and thought streams have stopped.
The researchers specifically wanted to know:
What does this state of being “clear but without thoughts” look like in the EEG?
How was the study done? The design in a nutshell
Who were the participants?
The study included 20 experienced Sahaja Yoga meditators, men and women, mostly between 20 and 40 years old, right‑handed, and with a regular meditation practice.
What did they do?
Each participant went through two main conditions while EEG was recorded:
Eyes‑closed rest
Simply sitting quietly with eyes closed, not meditating intentionally.
Meditation
Practicing Sahaja Yoga as they normally do, aiming to enter thoughtless awareness / mental silence.
From each condition, the researchers selected artifact‑free EEG segments (without blinks and muscle noise) for analysis.
What did they measure?
Using 62 scalp electrodes, the study performed two main types of analysis:
Linear analysis: spectral power
EEG was decomposed into several bands:
theta‑1 (4–6 Hz), theta‑2 (6–8 Hz), alpha‑1 (8–10 Hz), alpha‑2 (10–12 Hz), and three beta bands.
The team examined how power in these bands changed in different regions, especially along the midline frontal, central, and posterior (occipital) areas.
Nonlinear analysis: Dimensional complexity (DCx)
Using a standard algorithm (PD2i), they calculated DCx as an index of neuronal computational complexity.
They focused particularly on midline anterior frontal (mAF) and midline fronto‑central (mFC) regions, since their earlier S13 work showed these areas are most affected by meditation.
Main finding 1: during meditation, frontal complexity really drops
Comparing meditation to rest, the researchers found a clear and focused change:
DCx over midline anterior frontal and central regions significantly decreased during meditation.
This means fewer independent neural processes were active in those regions at the same time.
The frontal cortex no longer behaved like a crowded “multi‑tasking hub” with many processes running in parallel.
They interpreted this as follows:
During meditation, the brain needs to sustain controlled, internalized attention instead of letting attention drift outward.
At the same time, it must suppress irrelevant stimuli and thoughts.
This kind of state naturally leads to more convergent, less complex activity in frontal regions.
In terms of our traffic analogy:In everyday life, your brain may be running dozens of “traffic flows” at once.In a successful meditation session, many of those flows are shut down, leaving only a few important routes operating – and that is what the drop in DCx is capturing.
Main finding 2: theta and alpha get stronger over frontal areas
Interestingly, while complexity decreased, some brain waves actually became stronger.
During the meditation condition, the study found that:
Theta‑1 (4–6 Hz) and theta‑2 (6–8 Hz)
Showed clear power increases over anterior midline regions (such as AFz, Fz).
This pattern is commonly interpreted as reflecting focused internal attention and emotional processing.
Alpha‑1 (8–10 Hz)
Also increased over anterior midline regions.
Such low‑alpha synchronization is often taken to mean that external attention is being switched off and internal attention is being engaged.
Alpha‑2 (10–12 Hz)
Showed a focused power increase over the posterior occipital region, which is linked to visual and higher‑order integrative processes.
These findings dovetail with the earlier S13 study:
During Sahaja Yoga meditation, theta and low‑alpha activity over frontal and midline regions increase, reflecting internalized attention and an emotionally positive state.
Main finding 3: the more “meditative” the waves, the lower the complexity
The researchers then correlated DCx with spectral power in various bands during meditation:
DCx was negatively correlated with theta‑2 and alpha‑1 power
The stronger theta‑2 and alpha‑1 were, the lower the complexity.
In other words, as the frontal networks associated with concentration and inward awareness became more synchronized, the number of parallel neural processes decreased.
DCx was positively correlated with beta‑3 (22–30 Hz) power
Higher beta‑3 was associated with higher complexity.
This suggests that more analytical, restless or “busy” modes of brain activity might go hand‑in‑hand with a more complex, noisier pattern.
From this perspective:
Sahaja Yoga meditation does not make the brain “shut down.” Rather, it reduces unnecessary activity, while strengthening a few key networks related to inner awareness, positive mood and focused attention.
Translating the results into everyday language: from “messy multi‑tasking” to “one clear, quiet channel”
Putting all the findings together, we can picture the brain like this:
In everyday mode:
The frontal lobes behave like a computer with many apps and browser tabs open, notifications popping up constantly.
In EEG terms: relatively high DCx, with many independent networks active at the same time.
In Sahaja Yoga thoughtless awareness:
Many of these “background programs” shut down.
What remains are a few key “foreground processes” associated with inner clarity, positive emotion and stable focus.
In EEG terms:
Theta and alpha become stronger over frontal midline regions.
DCx drops in those same areas, indicating a more streamlined, orderly pattern of activity.
This picture resonates very strongly with how Sahaja Yoga describes the state of mental silence:
The mind is quiet, unnecessary thoughts stop, but awareness is bright and clear.
Why does this kind of research matter?
This study is important for several reasons:
It does not rely solely on subjective reports like “I felt good” or “I felt peaceful.”
It uses high‑density EEG, controlled conditions and standard statistical methods to measure clear differences between rest and meditation.
It moves beyond “Are the brain waves stronger or weaker?” and asks “How does the structure of brain activity change during meditation?”
Together with the earlier S13 study, it offers a more complete picture:
S13: which brain waves and connections light up in meditation.
S21: how the overall pattern becomes less noisy and more organized.
Importantly, the authors are cautious. They do not claim that meditation cures diseases.Instead, they show that:
The inner experience of Sahaja Yoga meditation – especially mental silence / thoughtless awareness – can be detected as a reliable, measurable change in the brain’s activity patterns.
If you are curious about this “clear but thoughtless” state…
The point of this research is not to tell you that you must practice a particular method.Rather, it offers a scientific glimpse into what happens when we genuinely quiet the mind, feel emotionally positive, and keep our attention stable inside.
It suggests that:
The brain in such a state is not empty or shut down.
It is selectively active: it switches off a lot of internal noise while allowing a few key, integrative networks to function smoothly.
If you are curious about how Sahaja Yoga actually teaches this state of mental silence / thoughtless awareness, and about its chakra and energy system model, you can explore other pages on the website for practical instructions and background information.
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