Brainwaves: Altered States & Technologies
Right now, as you read this, your brain is producing brainwaves.
What are brainwaves?
Simply put, they’re electrical signals.
Each second, your brain generates millions of these electric impulses. They pass between neurons, or brain cells, that connect in intricate systems.
You can picture your brain activity as changing weather patterns. Networks of neurons fire like charged storm clouds. And this happens at certain frequencies, which we measure as brainwaves.
They can tell us a lot about what's going on in your mind. First, let’s look at how neuroscientists categorize brainwaves.
Brainwave Types
There are five main brainwave types: gamma, beta, alpha, theta, and delta (see chart below). Each has a different frequency range.
Different brainwaves correspond with particular states of mind. (Note: These Greek letters are confusingly out of alphabetical order since some were discovered earlier than others.)
Generally speaking, we spend most of our day in a beta brainwave frequency. It's characterized by active thinking, problem-solving, ruminating, and focus on tasks. Essentially, beta waves signal that you're in Doing Mode.
If you close your eyes, you might slip into an alpha state, becoming calm and introspective. Alpha also marks a creative zone, and it's the one you're in every night before falling asleep.
Meditators demonstrate even slower brainwaves, slipping into increasingly relaxed, yet still alert, theta frequencies (more on this soon).
When your brain produces slow delta waves, this generally means you're in deep, dreamless sleep.
Finally, high-frequency gamma waves often come in brief moments of heightened awareness and insight, like when you bite into delicious food or solve a crossword puzzle.
Meditation Research
Since meditation produces an altered state of mind, it's no surprise that we'd also see major changes in the brain.
Studies show that brainwaves in meditation are primarily in the alpha and theta range.[1] Applying neurophenomenology (first-person experience, as popularized by Dr. Francisco Varela), it's probable that you're down-shifting from anxious beta into more tranquil alpha and theta states.
But the patterns are different depending on the type of meditation, like Focused Attention (dharana), Good Vibes (metta), Open Monitoring (vipassana), or Mantra (like TM).[2] For example, Focused Attention requires more active control, while Mantra is comparatively effortless.
Also, the brainwaves in meditation may vary based on the skill of the meditator and the amount of time meditating.
Although the research is limited, neuroscientists have found remarkable changes in "Olympic-level" meditators who’ve clocked over 12,000 hours of practice. Cutting-edge research found that they produce significantly more gamma brainwaves than an average person, even after formally meditating.[3] This study and others suggest that long-lasting altered traits are possible with training.
As Dr. Daniel Goleman explains, the average person might experience momentary gamma wave activity when an insight comes, but some highly-trained meditators live in this state all the time. He also mentions that a compassion-based technique (Good Vibes, taught on the FitMind app) increased their gamma waves by 7-8x.
Brainwaves in Sleep & Flow States
Let's briefly look at two other major altered states of consciousness and their accompanying brainwaves: flow states and sleep.
A flow state is a feeling of complete presence and effortless action without the sense of a doer.
Like the neuroelectric signatures of certain meditation techniques, researchers found that flow states tend to bring the brain into alpha and theta frequencies.[4] Activity in the Upstairs Brain, your prefrontal cortex, quiets down temporarily.[5] There's probably a link between coming out of the Mini-Me's narrating mind and this shift into slower alpha and theta brainwaves.
Deep sleep (stages 3 and 4) drops you into even slower delta brainwaves at 0.5-4 Hz. You're basically in a mental blackout during this period. According to Dr. Matthew Walker of UC Berkeley, the slower brainwaves during sleep may help bring information between distant brain regions.
Amazingly, scientists found that a famous Yogi, named Swami Rama, could maintain conscious awareness while entering deep delta wave sleep.[6] Rama used an ancient Yogic meditation technique (Yoga Nidra, taught on the FitMind app) to enter delta sleep while still recalling external events. Much more research is needed in this area.
Measuring Your Brainwaves with EEG Technology
One of the inherent challenges of mental training compared to physical exercise is that it lacks tangible outcomes. Results don’t show in the mirror. There are no record-setting weights nor times to set.
Thankfully, the neuroscience of brainwaves lends some quantifiability that could soon provide accurate feedback on one's meditation practice. Tools such as the electroencephalograph (EEG), which measures electrical activity in the brain, give us clues about what’s taking place during meditation.
Here's a recording of my brainwaves in meditation. Each line on the graph represents a different brainwave frequency.
Brainwaves captured using a clinical-grade electroencephalogram (EEG) called Muse.
It's essential to bear in mind that these technologies, and neuroscience as a field, are in their infancy. EEG has a good temporal resolution (real-time measurement), but lacks spatial resolution, picking up aggregated signals from the outside of the skull.
As an analogy, EEG technology is similar to placing a microphone outside of a sports stadium and trying to figure out what's happening on the field from the cheering of the crowd—it's helpful but rudimentary. While we can peek under the hood at our inner mental mechanics, we're still living in the Dark Ages of brain science.
Another problem is how to interpret this data. While it's helpful to know that brainwave patterns correlate with different states of mind, this doesn't indicate causation or present a perfect mapping.
Although neuroscience still has a long way to go, we can know for sure that significant change occurs in the brain during meditation, sleep, flow states, and other shifts of consciousness, as indicated by our brainwaves.
P.S. — For in-depth mental fitness and meditation training, check out the FitMind app.
Sources:
[1] Kaur, C., & Singh, P. (2015). EEG derived neuronal dynamics during meditation: progress and challenges. Advances in preventive medicine, 2015.
[2] Lee, D. J., Kulubya, E., Goldin, P., Goodarzi, A., & Girgis, F. (2018). Review of the neural oscillations underlying meditation. Frontiers in neuroscience, 12, 178.
[3] Lutz, Antoine, et al. "Long-term meditators self-induce high-amplitude gamma synchrony during mental practice." Proceedings of the national Academy of Sciences 101.46 (2004): 16369-16373.
[4] Katahira, K., Yamazaki, Y., Yamaoka, C., Ozaki, H., Nakagawa, S., & Nagata, N. (2018). EEG correlates of the flow state: A combination of increased frontal theta and moderate frontocentral alpha rhythm in the mental arithmetic task. Frontiers in psychology, 9, 300., just like meditation.
[5] Dietrich, A. (2004). Neurocognitive mechanisms underlying the experience of flow. Consciousness and Cognition, 13(4), 746-761.
[6] Parker, S. (2019). Training attention for conscious non-REM sleep: the yogic practice of yoga-nidrā and its implications for neuroscience research. Progress in brain research, 244, 255-272.