Tech Talk by Dave Siever
Fundamentals of EEG & ADD
In this issue we are learning some fundamentals of a normal EEG under various conditions versus that of a college student with ADD. All of the following charts and figures were collected from the Mindset and processed on the Skil database.
In the topometric chart below, notice the micro volt (uv) levels for the various conditions. Also notice that all brain wave activity is smaller along the sides of the head (F7, F8, T3, T4, T5, and T6). This is because the reference electrodes are attached to both ears. Active electrodes at sites near the ears share similar activity to what is on the ears, thus canceling out some of the signal. These side areas are also near several neck muscles and the dreaded temporalis muscle which can inject a lot of artifact into the EEG, especially during reading and math tasks or when your client is nervous (a few good jokes and a relaxation process can help plenty). Notice that EC alpha is about 20 - 30 uv and that it suppresses as attention increases. However, during the math task, alpha has dropped by a ratio of 4:1 between the math and EC conditions. Also notice the muscle artifact on O1 caused by neck tension during the reading and math conditions.
Beta activity doesn’t change very much between tasks as indicated in the topometric chart shown on the left. Notice on the micro-volt scale that beta amplitudes are about 1/4 the amplitude of alpha activity during rest. Much of this beta activity is from 5 - 7 uv in amplitude and shows little suppression during attention tasks.
Notice high EC theta activity of up to 28 uv in this struggling college student when her eyes are closed. Also notice increased theta (inversion) is noticeable during reading (as compared to eyes open) indicating the "fogging" and loss of attention she experiences.
Following an 8 Hz AVE session, her EC theta fell to a much improved high of 19uv. During reading, her pre-frontal theta fell from 11 - 9uv, almost ending the inversion and her comprehension improved as well. Peak alpha frequency and A3/A1 ratios also improve (see Budzynski next section). AVE is also effective for inducing hypnotic trances where we can learn new study habits and emotions.
- dancing in the dendrites!