Gamma Neurofeedback: What the Research Shows

The brain is an electrochemical organ which operates through electrical signalling. Like an orchestral symphony, different parts of the brain produce different frequencies of electrical notes as they function.

The frequency band of Gamma, particularly 40 Hz Gamma, is particularly significant. This is primarily due to its connection to higher-order mental functioning, synchronizing timing in the brain, as well as indications that it is involved with keeping the brain healthy and young.

We can increase the power and synchronization of Gamma frequencies in the brain by stimulating the brain with light and sound. Stimulating the brain with sounds in the ears is called audio entrainment. Audio tapes and tracks using binaural beats have been available for decades, and EEG states have captured the imagination in the consumer marketplace.

We have become used to hearing about accessing the so-called 'Theta State' for creativity, the 'Alpha State' for relaxation, and the 'Beta State' for focusing on a task, and these phrases have gained popularity. But we rarely hear about the 'Gamma State'.

The reality in the brain is of course a bit more complex. There is no such thing as pure Theta or Alpha state, the brain produces all frequencies all the time, only the relative mix changes dynamically. Different parts of the brain produce different mixes as they perform quite different functions. Nevertheless, these phrases point out how the EEG reflects brain states. We know that we can increase Gamma in the brain by stimulating it with pulsed light, called photobiomodulation.

What is the advantage of neurofeedback training over stimulation and entrainment?

In stimulation, such as by using tones or pulsed light, we are stimulating the brain to produce the desired signals; the brain may or may not learn to produce the activity that created the signals by itself.

Imagine that you are training with the Sens.ai headset, with its sensors at significant places on your head, that are picking up your EEG. As you go deeper, the Sens.ai software on your phone lets you know when the Gamma activity increases or decreases.

This form of biofeedback, making you aware of the Gamma portion of the EEG signal of your brain, can teach your brain what a deeper state feels like, and how to enter these states faster and deeper.

Neurofeedback is a special form of biofeedback. With biofeedback, the technology informs the user that the target physiological parameter, for example, heart rate, skin electrical activity or blood flow is moving towards or away from the desired state.

That feedback provides the user with the information they need to either continue doing what they are doing (because they are heading in the right direction) or to make an internal adjustment to get them back on track.

This is like learning to ride a bike, once you receive clear feedback your body and your brain are experts at figuring out a path to move you into balance. Neurofeedback works with the EEG, the electrical signals produced by the brain.

Biofeedback and neurofeedback have been around for decades in clinics and have been used to teach relaxation, improve focus, reduce the symptoms of ADD, and deal with pain and headaches among other applications. These applications have been largely limited to the offices of highly trained professionals requiring expensive equipment and extensive training. This makes them largely unaffordable and inaccessible for the average consumer.

And it was hard to measure Gamma frequencies outside the skull due to high-frequency attenuation by the skull and muscle tension signal contamination. As a result, the early meditation research studies and clinical practice were limited to looking at the Alpha, Theta and Beta bands.

The most popular clinical databases have been limited to approximately 30 Hz, and so Gamma training is still not popular with clinicians. Consumer-level equipment has not had the sophistication to do any kind of real neurofeedback training much less Gamma training. Gamma was the least studied wavelength of EEG but that has changed with Sens.ai.

Gamma power and synchrony have been shown to increase in high-performance cognitive and meditative states. In fact, musicians, meditators, and mathematicians have all been shown to have higher resting Gamma power in their brains^1,2,3. Gamma has been particularly implicated in processes that coordinate information from different parts of the brain⁴.

Also, 40 Hz Gamma is being studied for its ability to "take the garbage out" in the brain by activating glial cells and reducing age-related cognitive decline. Early human clinical trials using 40 Hz light and sound stimulation showed reduced hippocampal atrophy, improved delayed recall, and increased connectivity in the default mode network in patients with mild Alzheimer's dementia⁵. A 2025 systematic review in Translational Psychiatry confirmed the safety and emerging efficacy profile of gamma sensory stimulation across the published literature⁸. One purpose of these frequency signals is to coordinate the activities of different parts of the brain as they cooperate. Using neurofeedback we can train different notes in the brain signals up or down in power and timing for different performance outcomes.

So can we effectively train Gamma frequency signals in the brain and help people develop cognitive and meditative skill? Currently, available research-grade equipment is capable of faithfully picking up signals up to 70 hz (with very expensive equipment). Even though these signals are attenuated by the skull, they can be successfully used for training. Consumer-level equipment that can pick up and train Gamma has, up until now, been non-existent.

The Sens.ai headset is the first consumer-level device that faithfully reproduces signals in the range of 40-50 hz from the brain and has built-in programs for Gamma neurofeedback training. The combination of neurofeedback and pulsed light (photobiomodulation) is what makes Sens.ai particularly distinct.

So how do Sens.ai’s Gamma neurofeedback programs work?

Sens.ai begins by recognizing that Gamma waves ride on Theta and Alpha waves. This phenomenon is called cross-frequency coupling. For example, when a memory is retrieved from the hippocampus, a combination of low-frequency theta and high-frequency gamma waves are involved in the retrieval of the memory⁶.

So the neurofeedback training is carried out in a recommended progression through multi-week Missions that train the user in various combinations of theta and gamma or alpha and gamma frequencies or theta, alpha and gamma at once, as well as gamma alone. This layered approach reflects how the brain's frequency bands actually function together.

Also, the electrode placement where the training is done is important. Different brain areas participate in functional networks communicating together to perform various functions. The brain contains some highly interconnected nodes, which are also connected to each other in what is called a rich club network.

The Sens.ai headset uses electrodes located on some of these important hubs such as the superior medial frontal/dACC cortex and the medial parietal/PCC cortex ⁷. This enables Sens.ai to train the parts of the brain that have a significant impact on its overall functioning.

Besides neurofeedback, Sens.ai uses infrared LEDs placed at locations participating in the rich club network. This combination of photobiomodulation with neurofeedback training supports measurable gains in cognitive performance and cognitive longevity.

References

1. (2017, January 24) Increased Gamma Brainwave Amplitude Compared to Control in Three Different Meditation Traditions

2. (2014, June 11) Optimized Gamma Synchronization Enhances Functional binding of Fronto-parietal Cortices in Mathematically Gifted Adolescents during Deductive Reasoning

3. (n.d.) Long-term meditators self-induce high-amplitude gamma synchrony during mental practice

4. (n.d.) Neuronal gamma-band synchronization as a fundamental process in cortical computation

5. (2022, December 14). Gamma frequency sensory stimulation in mild probable Alzheimer's dementia patients: Results of feasibility and pilot studies. PLOS One.

6. (2015) Theta–gamma coupling in the entorhinal–hippocampal system.

7. ( February 5, 2014) Structural and Functional Rich Club Organization of the Brain in Children and Adults

8. (2025). The safety and efficacy of gamma frequency auditory and visual stimulation in the treatment of Alzheimer's disease: a systematic review and meta-analysis. Translational Psychiatry.