Entering the world of brain biofeedback or neurofeedback is like entering a world of strange words and alien ideas. My Brain Injury, Brain Training portfolio contains documents on the terms I use in my posts. Here, I explain brainwaves.
Brain biofeedback or neurofeedback works by giving you feedback on your brainwaves. The feedback tells you how well you’re inhibiting or enhancing certain brainwaves. I took the images below from my own brainwaves as they were being assessed in the week of 10 August 2015. I show two different locations to demonstrate that brainwaves look different depending on which part of the brain is producing them.
Your brainwaves can be inhibited or enhanced through training. In order of amplitude and appearance in the images from left to right, they are:
“A delta wave is a high amplitude brain wave with a frequency of oscillation between 0–4 hertz.” (Wikipedia) They are usually seen in stage 4 sleep (in the US, many have combined stage 3 and stage 4 sleep, but Canadian experts believe there is sufficient difference in these stages to keep them separate). Where the brain produces delta waves during the day when you’re awake, we call it snoozy. Basically, the brain is busy snoozing instead of working.
A theta wave is “in the 4–7 Hz frequency range, regardless of where in the brain they occur or what their functional significance is.” (Wikipedia) They are related to meditative states or when you feel like you’re in the twilight zone. Too much theta can reflect the effort required to focus or do a task, for example, like after brain injury. It can also mean it’s harder to tolerate annoying sensory events.
An alpha wave is “in the frequency range of 7.5–12.5 Hz.” (Wikipedia) The upper end at above 10 is considered high alpha. High alpha can have different effects than low, and so you may want to inhibit low alpha, that is, 7.5 to 10 Hz, yet at the same time, enhance high alpha, 11-12 Hz. This wave is associated with calmness and creativity. Alpha-wave intrusions, that is, alpha waves that pop up during sleep apparently interrupt sleep. So, according to current knowledge, they’re good during the day, not so good at night.
SMR: Sensorimotor rhythm. This is over the sensorimotor strip — the horizontal section of brain that goes across from ear to ear. “For most individuals, the frequency of the SMR is in the range of 13 to 15 Hz.” (Wikipedia) This area is the standard site of biofeedback training for relaxed, focused attention, as for example with treating ADD (Attention Deficit Disorder) and epilepsy.
When I talk about beta waves, it’s with the 16-20 Hz or more narrowly 15-18 Hz range. But a beta wave is in “the frequency range of human brain activity between 12.5 and 30 Hz (12.5 to 30 transitions or cycles per second).” (Wikipedia) As you can see, it includes SMR. The 16-20 Hz range is associated with problem solving. The range above 20 or 21 is also called “busy brain,” that wicked rumination state people with brain injury get into and have a tough time exiting. Round and round and round goes the same awful thought. Inhibiting the higher beta frequencies or “busy brain” helps to reduce rumination.
The gamma wave is the least trained and least understood. It is in the “frequency between 25 and 100 Hz, though 40 Hz is typical.” (Wikipedia) I think Wiki’s frequency range overlaps beta and EMG or muscle tension. But the rest of the article is worth a read. I am currently a guinea pig for training gamma waves at the 39 to 42 Hz range. It is the tiniest of all the brainwaves, and the electrical activity from muscle tension can easily drown it. You must be able to relax your muscles and be familiar with biofeedback training in order to be able to train this elusive brainwave. Two things it does from my experience: make you coherent; reduce your stress immensely. It has other effects too, as I’ve blogged, but those are the biggies for me.
Muscle tension. 52 Hz and above.
All your brainwaves together look like the above image. Notice how they do not look the same at different sites on your head, although with these two sites being not that far apart, they don’t look as different as other sites do. The FP1-F3 site is located on the forehead at the frontopolar region; the C3 is the left central area.
For further information, please click on the Wikipedia links given in the above paragraphs. You can reach the ADD Centre at their website.