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 briefly HRV.
Heart rate variability or HRV is a measure of heart health. It’s way more complicated than what I can understand or explain, but basically, the more the heart is in sync with your breathing, the better. HRV is a measure of that. (Wikipedia) Pink in the image shows the rise and fall of your heart rate; the blue shows your inhalations going up and exhalations going down.
HRV training is a way to both train your deep breathing skill and to induce relaxation. The ADD Centre begins each brainwave training session with HRV to relax the client. HRV training also helps to improve your heart health, I believe. The HRV amplitudes, as seen in the bars at the bottom centre of the image show you how you’re doing as well. You want the purple or middle bar to be the highest. The yellow bar indicates sympathetic activity (flight or flight) and the green, parasympathetic (laid back). The image above is what a good HRV should approximate, but mine is usually terrible. My breathing is “perfect,” as the trainers tell me, but my heart has a hard time getting in sync, as shown in the image below. It is, though, a whole lot better than it was when we first began HRV training.
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.
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 the letter-number terms I use when talking about what parts of my brain we’re training during brain biofeedback or neurofeedback.
The ADD Centre uses a 19-point full cap that uses the 10-20 system to assess your brainwaves. Each point on the full cap has its own term. The first letter denotes the area of the brain; the second letter or number denotes the location. Check out the image:
A1 and A2 — your ears — are the grounds, like the third prong in a plug.
Z stands for zero, that is, the midline. Odd numbers are on the left hemisphere; even on the right.
Locations for biofeedback training can also be in between any two of these points and would then use a combo name, eg, PzO1 would be lower than PZ, to its left, and above right of O1. The image below shows you the locations of these brain areas, looking at the right side of the brain. The cerebellum is underneath the other lobes, not up against the skull like them, and so there are no electrodes right over it.
“The 10–20 system or International 10–20 system is an internationally recognized method to describe and apply the location of scalp electrodes in the context of an EEG test or experiment. This method was developed to ensure standardized reproducibility so that a subject’s studies could be compared over time and subjects could be compared to each other. This system is based on the relationship between the location of an electrode and the underlying area of cerebral cortex. The “10” and “20” refer to the fact that the actual distances between adjacent electrodes are either 10% or 20% of the total front–back or right–left distance of the skull.”