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The neuroscience of meditation is an ever-expanding and evolving field. A huge amount of studies have emerged across a variety of disciplines demonstrating the advantages meditation provides toward brain health and life experience. As the science moves forward, we seek greater ways of both qualifying and quantifying what meditation is and how it interacts and changes the brain. As a meditation practice develops for an individual, they report increases in features like focus and compassion while reporting decreases in negative mental states like anxiety. As these negative states diminish and positive attributes become accentuated, these mental movements can become measurable.
Electroencephalography (EEG) is one way in which we can measure a component of the brain’s activity. EEG looks at the rhythmic activity of a subset of the brain’s neurons. Specifically, the upward oriented dendrites of pyramidal cells in the upper layer of the cortex. These neurons are a type of brain cell that fire electrochemical signals down fibers called axons. They communicate with each other and other cells by firing these electrolyte-driven signals down their axons, releasing chemicals at the terminal end into a space called a synapse. Within the synapse, these chemicals are picked up by the dendrites (mostly) of other neurons, stimulating them to increase or decrease firing their own electrochemical signal, thereby either propagating or inhibiting the conduction of the signal.
These signals operate in two ways, non-oscillatory and oscillatory, the latter being what EEG science tends to focus on. This oscillatory activity refers to the rhythmic quality of these electrochemical firings. When these neurons fire synchronously, they create what can be measured and deemed a brainwave. With EEG, when millions of neurons start to fire in synchrony in the upper part of the cortex, they create a tiny but measurable neural signal. This is what makes EEG measurement possible. For example, a few million neurons firing in sequence seven times per second can be measured on an EEG, the collective conduction of the signal creating enough brief regularity in the neural signal to be measured once that signal is decomposed and then amplified on a computer. When neurons fire in this way seven times per second, we can say it is a brainwave of 7 Hertz (Hz, Hertz = frequency of something per second). Through methodological study and qualification, scientists have identified that human brainwaves can be measured as being active mostly between a range of around 0.5Hz to around 60Hz. The vast majority of brain activity operates between 1–30Hz but can be measured up to and over 100Hz and as low as 0.1Hz.
All brainwaves are present at all times across mental and physical states. These different frequencies operate almost like letters in the alphabet or instruments in a symphony. Together, their interplay and interaction can describe aspects of our conscious experience and reflect our underlying physiology. No one is better than the other, these brainwaves changing on a second to second and day to day level as our brains shuttle between various networks, modes of thought, metabolic needs, energy levels, and so on.
EEG is a rapidly evolving field, with advancements in hardware, software, and understanding coming each month. The underlying understanding of meditation, too, is rapidly changing through study using EEG. Additionally, the advent of affordable consumer level EEG devices has led to much interest in the topic by a wide variety of individuals, particularly meditators who for the first time are presented with a potential tool for measuring internal mental states.
Brainwaves are often denoted by the orange symbols above. (From left to right: delta, theta, alpha, beta, and gamma.)
This short guide attempts an introduction to this lofty and ever-changing field by taking a closer look at each brainwave and how we currently understand it to be involved in meditation. Although there are many different brainwaves across a wide band of frequencies, this article focuses upon the five main defined bands: delta, theta, alpha, beta, and gamma.
Delta
When we think of delta, there are three key words which should come to mind: sleep, metabolism, and pathology. Delta, like all brainwaves, plays a key role in a wide variety of biological features. Delta, the slowest of the classically defined brainwaves typically oscillates between 0.5Hz and 4Hz. This slower nature begets its function in the brain as a wave that is more responsible for non-cognitive aspects of consciousness. Meaning, delta is not a wave which typically results in active thoughts and experiences in the brain. Its responsibilities are more bodily in nature. Sleep is the biggest realm in which delta dominates. Delta waves are not that present in the early stages of sleep but increase greatly as we get into deeper stages, being associated with the deep, dreamless, body-recovering segments of the sleep cycle, which then get lighter and practically disappear when we reach the shallower portions of our sleep cycle in order to dream. The delta found in these deep sleep segments is unique and has the role of releasing hormones into our brain to help the cleaning process as we recover from our day. In response to this deep sleep delta, our brains actually shrink about 20% during these times. This has the function of helping to clean the brain out as synaptic connections are adjusted and cerebrospinal fluid helps “wash” the brain from its daily labour.
Another role for delta is similar to above, but occurs even when we are awake, this feature having to do with metabolism. Metabolism is the operational enactor of balance that occurs in every living being. It is the umbrella term for the shuttling of blood and nutrients around the body in order to build or digest neurotransmitters, sugars, etc., move oxygen around, and generally, to support life. Delta can be a marker of this, although the relationship is not one-to-one. Often, ratios of delta among the other waves can be used in a waking context to evaluate a rough metric of brain health, seeing if the brain has enough resources to do what it wants to do. This is useful in the context of neural injuries, like stroke, which can dramatically cause damage and alter activity in the area of issue. Although, the science of this phenomenon is not well-defined, and so caution in making these interpretations is required, however, in the realm of pathology these delta-based measurements are becoming more common.
Pathology is the final, and major, component brought to mind when studying delta. Strong delta in the waking brain can be indicative of a brain injury. For example, if someone had injured their head and suffered a traumatic brain injury (TBI), or some sort of brain damage, the area of the brain damaged can be identified by the presence of delta waves where instead there should be a more active brainwave like beta. In neurofeedback regimes to help alleviate TBI, stroke, and other brain based issues, delta is often set to be inhibited and other brainwaves like beta are set to be increased to facilitate healing and recovery.
Lastly, in the realm of consumer EEG, delta is a large issue. Delta artifacts are perhaps the most common source of misinterpretation when it comes to consumer level devices, particularly those focused around the frontal lobes. Facial movements like blinks, slight head or eye movements, tongue and jaw movements, among others, contaminate the electrical signal read by the EEG device and are erroneously interpreted on the resulting graphs and data files. This is because these movements of muscles and nerves of the face create loud electrical signals that drown the tiny brainwave signals we are looking for. The algorithms and computing power of these devices are usually too small to account for this, often their designers lacked the knowledge of this, and filtering methods on consumers EEGs are relatively non-existent, users being forced to accept whatever stream of reported data is presented with little ability to check for signal quality, artifacts, and other methods which are a standard in EEG science. This often results in graphs and data which have little to do with the brain, being dominated by louder non-brain electrical signals that are forced through an interpretive system as if they were brainwaves, ultimately being presented as such. This results in many users of such devices finding that graphs of their meditation session, from the frontal perspective, are oddly dominated by delta waves, a result which has little to do with what’s happening in their brain. Through filtering of these graphs of consumer EEG through professional EEG programs, that delta can be removed and the underlying brain signal can sometimes be ascertained, but often it is seen that due to the volume of other sources of contamination, there can be little to no brain signal left for adequate and reliable analysis. In line with this, the above linked study on neurofeedback and stroke chose to omit reporting delta on their qEEG, citing these very reasons. Many studies across a wide variety of fields that use EEG are forced to deal with this common source of contamination. For an additional study that had to deal with delta artifacts, see this study on the effects of tea on brainwaves.
So, what is the role of delta in meditation? While all brainwaves are subject to individual nuance and the advancements of the field. Typically, striving toward lowering delta seems to be the common factor among deep meditations and experienced meditators. In this interview, Jeff Tarrant, founder of the Neuromeditation Institute mentions how in very deep states of meditation “delta plummets”. In addition, EEG results are always taken in context of their location, individual being studied, device used, and so on. Delta plummeting frontally is in line with some studies of Buddhist monks which found that a decrease in frontal delta and slight increases in central delta was associated with reduced processing of self-referential thoughts, moving them into spaces of serenity and compassion. This study forms an interesting, if long, read on the subject, although admittedly, the study is so old it lacks modern usage. However, interesting nonetheless. Especially as most modern studies will eschew delta in light of its high potential for contamination, making modern studies on the wave more difficult to find in comparison to other, more easily studied and cognitively-influenced brainwaves.
Overall, delta is a hard wave to study due to it’s “non-cognitive” identity and will be the subject of much advancement of understanding as the field of EEG-based meditation science further grows to understand it. Generally, in meditation, we are lowering delta, however in certain circumstances it has been seen that centrally-based delta increases in some forms of meditation.
Theta
Theta, typically measured between 4–8Hz, is a wave of great dichotomy in the context of meditation. On one hand, it can be a marker of depth, a wave often put upon a pedestal, on the other, it’s perhaps the most well-defined and common marker of cognitive fatigue, drowsiness, and lowered energy in meditation and attention science. As people continue to engage in a mental task, their theta rises in line with a sense of fatigue, lack of attention, and dwindling neural resources. This feature is used in a lot of different EEG studies. A common methodology is to check theta levels at various points, watching if they rise. If they rise, it means your study subject is starting to get bored and tired with the task and it may be good to either stop collecting data here or make some sort of note or alteration in light of the person’s lessening “brain energy” to be put toward the task. The more time a person spends “on-task”, the more theta naturally rises to match the increased fatigue and lowered attentional power. A common area where this is used practically is in studying fields where vigilance is key, an example being air traffic controllers, it being key to recognize when they start to get tired, their job demanding a constant state of readiness.
In the science of meditation, theta’s role in both depth and fatigue creates an analytical problem. Theta is commonly reported as a measure of depth in meditation. For example, Carmelite nuns, when connecting with their sense of the divine, exhibit increased amounts of theta, particularly among left frontal/central sites. This left-sided theta seems to be a common marker for depth in meditation, at least in some contexts. Then, the more general theta rising on both sides of the brain may be more indicative of the fatigue process, the natural results of time “on-task”. How to differentiate between the two forms of theta is still something to be nailed down. Arnaud Delorme, a large contributor to EEG science, recently released a paper which gives another clue. According to his research, another way we can tell if this theta is associated with neural fatigue is if it is seen to rise alongside delta brainwaves, providing another way we can potentially begin to discriminate between various modes of theta.
Personally, in my own research, I have found similar expressions of this left-sided theta alongside studying highly experienced meditators. Working with Kevin Schoeninger, co-founder of Raising Our Vibration and pioneer in the style of subtle energy meditation, I have seen this potential expression of depth manifest within the peak portions of his meditation practice. With many years of cultivating his practice, analyzing his 19ch qEEG during meditation provides many insights. As evidenced below in the graph of the power spectrum density (graph of neural power/synchrony over frequency) during the peak section of non-dual consciousness, depth, and connection, we can observe a shift toward more theta dominance, particularly around electrodes Fz, F3, F4, Cz, and C3, these being mostly left/centrally-located electrodes. Over the course of the meditation, which lasted almost an hour, the theta did non increase linearly, like what would be seen in a fatigue response, but moved more harmoniously with the sections of increased depth. This aligns and lends more evidence toward particular theta responses being key in differentiating meditators from day-dreamers.
Overall, theta, like all brainwaves, has multiple roles and responsibilities. For meditators, it is certainly one of the most interesting brainwaves. However, it often falls second, in my opinion and in the opinion of other neuroscientists, to the next brainwave in our sequence, alpha.
Alpha
Historically, alpha was the first brainwave discovered. It is typically defined between a range of 8–12Hz. For the most part, we can think of alpha as the wave of suppression. This underlines one of its most important roles, alpha often being indicative of parts of the brain entering a more idle, less active state. Perhaps the most well-known example of alpha suppression occurs when we close our eyes. Our occipital lobe, the rear portion of the brain responsible for the majority of visual processing, is quite active during the day as it deals with the large amount of visual information coming in any time our eyes are opened. When we close our eyes, this biologically expensive visual processing is not needed, and consequently, the faster frequency waves are dampened as a blanket of more subdued alpha coats the area. When we open our eyes, that alpha is promptly removed and faster frequencies return.
In regards to meditation, we are typically looking at alpha as it sits along nodes and networks of attention, focus, emotional affectation, and self-oriented processing. The most common way to relate the experience of alpha quieting these areas is in the experience of day-dreaming. That aloof, relaxed, mellow state correlates with and is influenced by alpha wave activity, particularly around the frontal lobe. As a result, alpha training is a common form of neurofeedback used to increase calm and general well-being among people who struggle to bring down and subdue parts of their brain, suffering from anxiety and having trouble relaxing in the moment. People with these issues can often be alpha “under-performers”, the training then bringing alpha back up, and with it, a more relaxed mindset. This is also why alpha is so key in meditation, and why meditation is such an effective and impactful way of cultivating a healthy state of mind. In Herbert Benson’s definition of the famous “relaxation response”, (a landmark study in the 1970s bringing the health benefits of altered consciousness to bear on Western medicine), alpha waves were a key measurement.
Calming the mind in meditation is like doing brainwave training that’s customized for our brain. In meditation, we use the power of our brain’s own natural ability to change and regulate itself over time, a feature called neuroplasticity. With practice, this cultivates many positive states like those of increased compassion, focus, energy, etc. and, over time, grooves them into more permanent traits.
Due to its role in a quiet mind, alpha is perhaps the most important brainwave to consider when studying meditation. Alpha, particularly on the lower end of the frequency spectrum, between 8–10Hz (sometimes called “alpha1”, 10–12Hz then being termed “alpha2”), appears to be a huge mediator of the meditating mind. Developing and refining healthy alpha activity seems to be a primary effect of meditation. Alpha, with its suppressive qualities, diminishes the chatter of anxiety, improves emotional stability and reduces reactivity, and in general, provides a healthy and reflexive relaxation from the chatter of higher frequency waves. Again, it is important to reiterate the nuance of EEG science, alpha having more complex interactions the more we consider factors like age, time of day, the style of meditation, and so on, but generally, increases in alpha predominate the expression of meditation.
Beta
Beta is easily most famous for being the brainwave of movement. The motor cortex, an area around the front/central region of our brains, operates predominantly in the beta range and is involved in planning and instigating the conscious movements of our body. This particular form of beta has been coined as the sensorimotor rhythm, or SMR for short, and is incorporated into a system using “mu” brainwaves (SMR-based alpha waves) that interact to coordinate bodily movement.
In terms of cognition, beta is most easily generalized as a brainwave of activity, often being seen in many active states of cognition like problem solving, critical thinking, focusing on tasks, and so on. Beta waves are quite variably defined in the literature and can range between 12hz and 30Hz. Like alpha, beta waves are sometimes divided up into various groups (Beta1, 2, 3, etc.) and change depending upon who is conducting the study.
Beta, very similar to gamma, is a wave of active cognition involving both positive aspects like focus and problem solving, and also negative aspects like lack of attention, anxiety, and so on.
In meditation, we’re generally trying to quiet these higher frequency waves. When we meditate, the role of active cognition takes a side step — the constant communication and association between regions becomes more subdued as self-oriented processing begins to diminish. In a very reductive way, beta and gamma are almost the inverse of alpha for meditators. As we try and relax our minds, beta/gamma reflexively come down in tone. At times, beta increases can be seen in early meditators engaging in more advanced styles, this being associated with the focus needed to follow specific instructions, engage in visualizations, and other protocol-learning based tasks. This beta then diminishes as those elements of focus become less needed and more automatic.
Beta can also be prone to muscularly-based artifacts coming from certain muscle groups, particularly the neck, jaw, and behind the eyes. The higher beta frequencies tend to be most susceptible to this, starting roughly around 20hz, leading up into the more commonly understood gamma artifacts in modern neuroscience. In the next section, we will go into more detail on this phenomenon.
Gamma
Gamma in the human brain, like all brainwaves, has many well-defined roles in modern neuroscience. Gamma, a higher frequency wave like beta, is often a wave of active cognition, a “thinking” wave. Sometimes, too much, gamma activity being a hallmark and useful measure of anxiety, attention-deficits, trauma, and in extreme cases, epilepsy, among many other roles. For these reasons, gamma is commonly a wave trained down by neurofeedback protocols, healthy gamma helping to maintain the wellness of the racing minds we tend to develop as humans of the modern “always-on” era. It can also be targeted for up-regulation in the spirit of improving elements of cognition. However, the efficacy of these treatments is variable, beta waves showing more “trainable” effects on consciousness in experimental trials.
Gamma, historically, the wave of mystery. The interpretation of gamma has seen the most change in EEG science over the years. This is due to the difficulty gamma’s low power/high frequency nature puts in front of researchers, the exact opposite of the higher power/lower frequency dynamic seen in other brainwaves. It takes a well-managed EEG system in order to wade into the pools of gamma and see what is really there. In the past, older professional-grade EEG systems struggled to maintain aspects like the sampling rate, data transmission bandwidth, and other such factors needed to study gamma properly — issues now heavily prevalent in modern consumer-grade EEG systems. Many studies, like this one, which use portable devices like Muse, are forced to discount their gamma results in relation to the inadequacy of the device and the common level of signal contamination seen in the gamma range.
Additionally, modern neuroscience now knows that the frequency spectrum of gamma waves in the brain heavily overlaps with the frequency spectrum of muscle activity, particularly around those of the eyes and neck, yielding calls to revise and take many gamma-based studies with caution. This commonly leads to muscular artifacts arising in the signal of EEG electrodes located around the very front and rear of the skull. Fortunately, these types of artifacts are becoming well-defined as time passes, computational methods (like independent component analysis) now being available for their removal. With these new techniques, the understanding of the many positive and negative aspects of gamma are being elucidated.
Gamma is typically defined as any brainwave greater than 30Hz. However, definitions for the limits of gamma commonly change between studies. Care should be taken to note the differences in methods between two studies measuring gamma, as they may be looking at alternate definitions. Some will define gamma as being between 20–30Hz, others group 30–50Hz, 30–100Hz, 25–45Hz, and so on as their discretion decides, also influenced by their expectations and level of experience with EEG.
What are we looking for when evaluating gamma within meditation, would we expect it to go up or down? The answer is both, and neither. Like answering this question for all brainwaves, the answer depends very much upon the context. Typically, meditation has been well-defined as showing gamma decreases correlated with the “quiet mind”, gamma lowering considerably in central/parietal regions in experienced meditators, or sometimes showing no movement. However, undulations in gamma are also noted within a single session over the course of a meditation. While the increases in gamma are still tiny compared to the higher amounts of gamma seen in baseline, increases in gamma along rear portions of the brain have been noted alongside reports of increased clarity of experience, an effect correlated with the activity of the brain’s visual processing centers.
The role of gamma in meditation has changed the most in modern studies. Consequently, many interpretive myths have cropped up around its nature. Previously, much was made regarding large frontal gamma increases within the brains of experienced meditators. An old study by led by Antoine Lutz in 2004 was perhaps the biggest influencer in popularizing the idea that advanced meditation was associated with large upward swings up gamma. However, this study is commonly cited but rarely replicated using the modern lens of EEG science. The study, if computed with the current-day understanding of EEG processing, would likely yield results more in line with gamma activity found in modern studies. The huge gamma activity found in this study’s practitioners was later understood to be contaminated by muscular artifacts that at that time were not fully understood, a finding supported by many different modern publications, from studies purely evaluating the nature of muscular artifacts to those which repeated similar measures to the Lutz study in advanced meditators.
The origin of these high-frequency gamma artifacts comes from the facial muscles, mostly those around and behind the eyes. Eye movements and stimulation create retinal-dipole artifacts; absorption into meditation coincides commonly with saccadic movements (unconscious eye movements behind the eyes), among other non-brain subtle electrical activity (more discrete movements, like infrequent blinks, can create low frequency artifacts, particularly in the delta/theta range, mentioned above). These signals can be erroneously grouped into the EEG brain signal and without proper removal, will yield largely erroneous data in the resulting analyses and graphs. This typically demonstrates as a large increase in higher frequency brainwaves among frontal regions, which is counter to the direction of gamma we expect from deep meditation. One of the hallmarks and ways of distinguishing these sorts of artifacts is by their location. On multi-electrode set-ups, frontal gamma artifacts are most commonly distinguished as they occur frontally, on electrodes close to the eyes. Rear electrodes are susceptible in the very back, on electrodes located closest to the neck, to similar issues regarding signals from neck and jaw muscles.
The resulting misinterpretation of brainwaves led to the popularization of the myth of “supercharging” gamma — high gamma being associated with deep mystical states or the presence of some sort of ethereal energy. Only now, in 2021, is this myth’s spurious origin being more commonly understood as researchers in the fields of neuroscience and meditation move forward and the evidence showing how gamma behaves in meditation becomes more clear. The myth was so pervasive, I personally would have trended in its direction if queried a few years back. The more modern understanding of gamma in meditation aligns with what we may expect, being more in line with the findings in the field of EEG neuroscience as a whole.
As mentioned above, gamma, in deep meditation, is profoundly diminished compared to normal waking gamma. A landmark study in defining the role of gamma in advanced meditators was published in 2017 by Schoenburg et al. in collaboration with noted researchers in the field, Dan Brown and Judson Brewer. They found that gamma activity will raise over the course of a 60min meditation, but is remarkably smaller than gamma found in the waking baseline. The highest gamma in the depths of meditation is still highly diminished compared to a resting baseline. This toned-down gamma response to deep meditation is associated with a dissociation from modes and centers of self-referential processing, leading to the deep and sometimes non-personal and non-dual experiences reported in these states. Diverging from the prevalent myth of raised gamma, the study makes its own reference to gamma artifacts, including a section discussing that,
“modulation within gamma-frequency may be associated with muscular artifact under certain circumstances. Indeed, upon entering meditation, gamma band decreased, although, current density decreased across all bandwidths examined (i.e. alpha, beta, and gamma 1 + 2), and to statistically significant levels for beta and gamma.”
They further went on to mention that,
“More importantly, gamma current density did not significantly increase within frontal sites, wherein increased muscle tension is often reflected in these topographically placed electrodes”,
further noting the common gamma artifact issue seen in meditation studies by some of the field’s thought-leaders.
The prevalence of the gamma artifact and the interpretive myth it’s created is not unique to meditation, but is common across a variety of EEG-based fields of study. Dreaming is one particular field where gamma has been misinterpreted and incorrectly allocated, coming under scrutiny in modern studies. In the fascinating, expanding, and developing understanding of lucid dreaming (developing waking-level consciousness in a dream-state), lucidity within a dream state was once thought to be associated with large gamma oscillations. However, recent studies and reviews have found this gamma to be associated with similar artifacts as are seen in meditation. Removing these artifacts, it’s now understood that dream lucidity is associated with the increased activity of low-beta (12–15Hz beta), which was occluded in clarity by the previous gamma artifacts. (For an excellent review, see this study.) This also explains the lack of efficacy found in devices marketed and sold to generate dream lucidity and need for greater amounts and quality of research. Personally, I recently consulted on a project related to patient care in healthcare and EEG and one of the considerations and confounding factors was gamma artifacts induced by patients exhibiting certain subtle facial expressions. Speaking with peers in various areas of study and looking at the literature, it is clear that this gamma artifact issue is highly prevalent and requires consideration across many fields employing EEG.
All brainwaves in meditation can change to go both up and down depending upon the location and function we’re considering, particularly being influenced by the style of meditation. So what sort of meditation would be seen to increase gamma waves and where? There’s a common misconception in regards to thinking that “high-energy” meditations employing forces of vital energy like chi and prana would somehow manifest as an increased gamma brainwave. A popularized piece of pseudoscience that is incongruent with the way brainwaves work and also with the studies on those forms of activity/meditation. In reality, the relationship goes in the opposite direction with these types of practices having very relaxing effects on the body and mind, causing gamma to decline to support the meditative mindset and deep experiences that follow. For example, in this study on the ancient Chinese practice of Qigong, which is centered around the movement of vital energy, or chi, practitioners were seen to exhibit very low levels of gamma throughout the practice. In fact, to really illustrate this, it was found that there were higher gamma readings from the people watching a video of Qigong compared to those actually engaging in either a physical or mental based Qigong session, particularly around frontal electrode sites. Qigong was marked by an increase in alpha activity among both the physical/movement-based practice and the seated, meditation-style, practice. In the mental/meditation oriented practice, theta was seen to increase and become a marker of the heavily internalized state induced by these practices.
However, as we’ve also seen, there are cases in which gamma rises. Gamma from the occipital region of the brain seems to correlate with experience with some styles of meditation like Vipassana and Himalayan Yoga, where it is seen a trait-wise increase in rear-brain activity above 60Hz. This is associated with a sense of increased clarity in meditation. However, for users of consumer EEGs like Muse and Flowtime, it should be noted that this sort of gamma is not registered by these systems due to how they process their data and the nature of their headsets, these being quite limited in non-laboratory contexts seeking research-grade data. Another great example of gamma comes from the above mentioned Schoenburg study, which found nuanced gamma undulations they associate with the anterior cingulate cortex (ACC), an area important for emotional labeling of experiences, and the precuneus, and area implicated in the processing of the self, a hub of the default mode network. Interestingly, they found this to diverge from beta brainwave activity in the insula, an area on the inside fold of the temporal lobe involved in many different aspects of consciousness like pain, emotion, craving, among many others. Together, this points to a decoherence between various brain networks and regions, particularly those involved with processing thoughts about ourselves, leading to deep experiences where, as they say, we are “free from doing.”
So what are we looking for when we’re studying these deep states in regards to gamma? Overall, lowered gamma seems to indicate decreased self-referential processing, particularly when seen along central electrodes, which is very evocative and works well with the low-frequency alterations in activity seen in advanced Buddhist meditators, potentially indicating a lowered metabolic activity in these areas. In this line, in more medically-oriented studies, gamma is increasingly being evaluated as a measure of glucose metabolism in the brain, gamma activation denoting active sites of cognition, and consequently, sugar metabolism by brain cells. Diminishing gamma seems to move and align the conscious mind to experience the deep, mystically-oriented states that come when the self is removed. Higher gamma, when of brain origin, is associated with more active “self” states of cognition. These states can be both of a positive and negative affectation. Positive being more associated with active cognition whereas negative is associated more with states of anxiety, panic, and trauma. However, again, within the largely subdued gamma activity in meditation, undulations in activity are seen which can correlate to aspects like clarity of experience.
However, the reality of gamma, and all brainwaves, is more complex and becomes a very nuanced feature that is unique to each individual, their age, their health, their experience, and expectation (and even transient factors like adjacent technological interference, oxygen levels, or even altitude).
The field of meditation is ever expanding, as is the science that helps define components of it. A key consideration for everyone interested in the field is to get used to adopting the humility required to keep pace, and the pace is quick. In the advancing tide of knowledge, castles of understanding fixed upon antiquated data will not stand the test of time. Fanciful, hyperbolic marketing of products and devices to “supercharge” brainwaves or drive biological features of mysticism pale and fall flat as the science reveals their misguided and often manipulative nature. Be mindful of the capitalistic nature of consumer marketing; even the most revered scientists and mystics in the field of meditation and consciousness will admit to not having all the answers, pointing to our rapidly expanding knowledge, which shifts paradigms and expectations every year as we learn more about how the brain works. Devices that purport to supercharge your mind to new levels with brainwave entrainment routines that lack the proper evaluative and diagnostic components seen in neurofeedback should be cautioned against. As humans, our brains, and our brainwaves, are so unique to ourselves that trying to get ourselves to conform to a standard set by another without proper evaluation is simply an exercise in futility. Brainwave modulation without a qualitative EEG (done on proper hardware) done first is like setting a person up for a diet and weight-training routine for someone who could be twice their size, or maybe half their size. At best, it’s ignorant, and at worst, I have seen it be harmful. Taking a singular study, piece of imaging, or data to justify an assertion is always dangerous and so for those along the path of understanding their own brain, my advice is to not set a brainwave goal at the outset, but to remain open as we all learn together about what makes us us. Charlatans lurking in the areas of scientific ambiguity have been around for hundreds of years. Meditation and related wellness is a multi-billion dollar industry in 2021 and neurocentric devices and companies that have “figured it out” are abound, ready to capitalize on this rapidly expanding consumer bubble. For a great read on the subject, check out Brainwashed: The Seductive Appeal of Mindless Neuroscience.
As scientists, we do not yet have the answers, throwing caution to those companies who would sell the answers to those seeking relief from their world weariness, health concerns, and other personal issues which can make us vulnerable. EEG focuses only upon one small aspect of neural activity from a subset of cells in the upper cortex. While it has been found to be incredibly useful, it is but one among a myriad of neuroimaging modalities, all which give a small, biased, piece of information. Taken in isolation, these various modalities form intellectual silos among people as they gather into the various camps of what they think is best. However, in my opinion, the future of consciousness science lies within the unification of fields.
Personally, as a neuroscientist and consultant in the field, I am constantly required to update my knowledge to be congruent with the latest studies by peers alongside my own work. As mentioned, if you’d asked me years ago about gamma and meditation, I would have stuck more with the old 2004 article from Lutz et al. mentioned above, however, with the latest papers and results from some of the titans in this field, alongside my own research, that understanding had to be reworked and consolidated in the context of the advancements in EEG methodology. Even this very article I expect to be antiquated in a year or two, necessitating I continue to incorporate and adapt to the latest understandings in neuroscience, as do we all. As we have seen and is readily verified, all brainwaves can move up or down in meditation depending upon the person and where in the brain you are looking. Consciousness and brainwave science is a moving ocean of water, to move with it is to swim amongst the tide, to remain still in understanding means to sink and drown.
So, overall, what should we be looking for when studying brainwaves while meditating? What should we expect and set as a goal? Expect nothing, be open, and explore. The goals and fruits of meditation grow internally, not to be shoe-horned into some small graph or data point. As both a long-time meditator and neuroscientist, the greatest advancements I felt in meditation came from separating myself from that analytical mind, the ego, in its insecurity, which seeks reassurance from other people, from devices, from anything to shield it from vulnerability. Again, whether the most intelligent scientist or most eloquent mystic, no one has all the answers. We can ask the questions, but perhaps instead of trying to fumble for an answer, we should listen and be open to make a space for the truth to come forward amongst our egoic human babbling. After all, is not that the point of meditation to begin with?
