To fully appreciate what is brainwave entrainment, let us first discuss what is brainwaves. Brainwaves, also known as neural oscillations are oscillating electrical voltages that reflect the neural activities of the brain. The brainwave frequencies are correlated with various states of consciousness or arousal of our mind. Scientists have generally classified our brainwave into 4 to 5 category, depending on the context of the discussion. The categories include:
- Delta 0.1Hz – 4Hz
- Theta 4Hz – 8Hz
- Alpha 8Hz – 13Hz
- Beta – 13Hz – 40Hz
- Gamma 40Hz and above are less discussed but this usually refers to frequencies beyond beta
Like electrocardiogram (ECG) for the heartbeat, our brainwave can be pickup with an electroencephalogram (EEG) device. EEG devices can use for both diagnostic and neurofeedback training uses. A product like Brainlink Lite is designed to easily visualize and quantify your brainwaves and use for alpha (meditation) and beta (focus) neurofeedback training for consumer use.
Brainwave entrainment is a term referring to the process or method using some form of external rhythmic stimuli to naturally synchronize one’s brainwave to the desired state. The external stimulation can be in the form of a visual, audio, tactile, or electromagnetic form. Studies have demonstrated that our mental state like alertness, stress or anxiety, or relaxation level can be directly influenced by the dominance frequencies of our brainwave, which also corresponds to our brains’ neural activities. The simplest example is music rhythm can influence our mental state. A slow tempo and light music can make us relax whereas fast beat music can increase our heartbeat and mental alertness state.
Brainwave Entrainment Source (Stimuli)
The most common sources of stimuli used for the purpose of brainwave entrainment are sound, visual, and tactile, as these are stimuli that can be picked up easily by our sensory organs. Audio entrainment, in fact, is one of the earliest and most ancient techniques used, even before the concept of brainwave entrainment is even discovered and understood by modern science. For instance, chanting practised by various religious groups like Buddist, Gregorian, Yoga, etc., all have the effect of monaural audio entrainment Today, we with the advancement of audio technology, audio entrainment technology has evolved into binaural and isochronic beats that offer more sophisticated audio entrainment technique. Visual (mostly through wearing a light flickering goggle) entrainment is another technique that is getting more popular. Visual entrainment practically is at least 2 times more effective as compared to audio entrainment, as our receiving sensory (visual cortex) is 3 times bigger than our audio cortex. The combination of audio and visual entrainment (AVE) is one of the most effective and cost-effective brainwave entrainment method available today. DAVID Delight from MindAlive Inc. is one such product that offers the combination of audio and visual entrainment in one simple and compact package.
A lesser-known source that in fact can be a very powerful stimulus is the pulsing electromagnetic frequency (PEMF). Brainwaves are naturally occurring electromagnetic fields in the brain due to neuronal activity. Brainwaves are measured in Hertz as they are electromagnetic frequencies, and can be influenced by the presence of pulsing magnetic fields. The advantages of using PEMF as entrainment medium is that PEMF is inductive. Hence you don’t have to “wear” the devices on your body in order to receive the stimuli. All you need is to place the PEMF applicator near you. For instance, you can place the PEMF applicator underneath your pillow or mattress, depending on the design of the devices. One popular PEMF device is EarthPulse, sleep-on-command. A more comprehensive product such as iMRS and Omnium1 from Swiss Bionic Solutions also comes with a fully integrated AVE Brainwave entrainment with PEMF solution.
Natural emitting frequencies minerals like crystal, rare earth materials also have entrainment effect, abide it’s rather subtle and is still not a well-studied subject due to the challenges of measuring the absolute frequencies in its absolute value. Technology again has also allowed us to create a device that can harness specific natural frequencies around us and amplified it through wearable like Philip Stein Sleep Bracelet. This is a subtle natural energy that may work on people that is more sensitive and receptive to it.