Behavioral Medicine Associates, Inc.

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Quantitative EEG and Neurotherapy Fact Sheet

Brain waves occur at various frequencies, that is, some are quick, some quite slow. The classic names for these "EEG bands" are delta, theta, alpha and beta. The dominant wave pattern you see above is alpha; these waves happen between 8 and 13 times per second, or 8-13 Hertz (Hz). Alpha represents a sort of "idle" state, or "ready but not doing much" state and is normally fairly large over the back third of the brain when the eyes are closed and when you are awake. Alpha disappears when we either get mentally busy (e.g., open the eyes, start doing intense mental work even eyes closed) or when we become drowsy. Thus the presence of alpha can show the presence of an awake, resting state. If it is present at a fairly high voltage when the eyes are open, this would usually indicate an inattentive, daydreamy state. In fact we often see this sign in adolescents and adults with attentional difficulties.

When we get mentally busy and engaged, we should see alpha "block," or reduce significantly in size. In its place we see mostly smaller, quicker "beta" waves. The beta family of waves happen at frequencies from 16-35 Hz, with higher frequencies known as "gamma".

Delta and theta waves are relatively slow. Delta is usually defined as waves occurring from 1-4 times per second (1-4 Hz). Theta occurs at 4-7 Hz. During drowsiness, first alpha disappears, then the size of theta waves begins to increase. As sleep begins, theta waves get quite large, then become mixed with and eventually give way to slower delta waves.

The presence of delta and theta waves in the waking, eyes open EEG is normal, but only if the waves are fairly small. High amplitude slow waves can be signs of various neurological and psychological problems, ranging from epilepsy to ADHD.

For years all that was possible was recording these waves on paper with the traditional polygraph. Over the last 25 years, advances in signal processing made it possible to sample these waves many times per second (usually 128 or 256 samples per second; our current equipment samples at 4096 per second) and to analyze them in various ways. Using this technology we can now measure precisely the amplitude and frequency of waves of interest, be fairly exact about the scalp distribution of the waves, and even compare a client's qEEG to a normative life-span wide reference database that shows how the person's brain activity compares, on the average across a particular task, to healthy people of similar age and same sex.

We use a 32 channel EEG system, the Truscan 32 by Deymed Diagnostic, which allows high quality digital recording as well as EEG biofeedback. The digital quantitative EEG (qEEG) shows the actual brain electrical events associated with periods of inattention very clearly, for example the under-aroused, "sleepy" signals. The recording below shows big "theta" waves over the front of the brain, indicating periodic "sleepiness" in these critical executive systems.

The excess theta pattern is the most common pattern seen in children with ADHD diagnoses.  About 60% show this pattern. This pattern is very responsive to the stimulant drug methylphenidate, since it "wakes up" the frontal and prefrontal cortex enough so that it can do the critical jobs of motivation, impulse control. Until the medication wears off.

Many adolescents, some pre-adolescents and many adults with ADHD diagnoses show too much alpha, with normal levels of theta. This is a different type of brain. The excess alpha pattern does not commonly respond to methylphenidate or amphetamine very well. The excess alpha pattern represents vast processing regions that are "awake" but are failing to "allocate" their resources to the job at hand. This causes the experience of "I heard your voice but I have no idea what you just said." The pattern looks like this:

This recording shows high amplitude alpha waves over most of the back half of the head. Notice the first example, the excess theta waves were over the front of the head (top four tracings plus the third one from the bottom).

Some people, often with more severe difficulties, show a mixture of alpha, theta and often delta waves. This next example is from an 11 year old girl previously diagnosed with Pervasive Devlopmental Disorder NOS, a major failure to develop age-appropriate social and academic skills:

Some of the big waves are alpha, the wider ones are theta and the widest ones are delta.  Contrast these patterns with the following example of entirely normal activation during a task:

Notice all the waves are much smaller. There are some little alpha waves, e.g. immediately above the word "normal", but they don't go on for a long time and they are not big. This indicates "pretty good" allocation of brain resources to the job.

You can see clear signs of over-excitement in some people, correlating with high anxiety.  The next recording shows an anxious adult female with her eyes closed. Notice there is very little alpha activity, but a whole lot of beta (the small, close together waves). This person was also diagnosed with "ADHD", but reacted very badly to a stimulant medication given by a physician who was simply "going by the book" and diagnosing ADHD by the symptoms, or complaints. Examining the QEEG would easily have suggested this person is already very aroused, over-excited and that anxiety and distracting thoughts were causing the inattention. Contrast this eyes closed "resting" recording with the normal recording at the top of this page.

WHAT ABOUT THE QUANTITATIVE PART, THE DATABASE?

First one must be able to read and understand the "raw data," the recording themselves (as in the examples above). Then, we select areas of the raw data that are free from "artifact" (eye movements, too much muscle tension, etc.). Those chunks of data are analyzed statistically. The size, frequency and coordination of the various waves are measured by the software (Neuroguide, by Robert Thatcher, Ph.D., http://www.appliedneuroscience.com) and presented as numbers and as statistical "brain maps."

Below is a statistical topographic map of the record above. The small dots on each circle represent the recording electrodes. Each separate circle represents the electrical power that was found at a particular frequency, e.g., at 1 Hz, 2 Hz, 3 Hz, up to 30 Hz. Notice the first row maps the 1-5 cycle per second (Hz) waves, the second row maps 6-10 Hz waves, etc.

ommonly found in anxious people. Settling this down (training for lower beta amplitudes, coupled with increased alpha activity) helps the person find a relaxed mental and physical state.

Below is a topographic map of a teen with an excess of alpha activity during listening. This alpha waxes and wanes, but on the average - which is what the statistical maps show - there is a major excess of it.


Thus we can see a physical reason for the inattention. We can also see which regions of the brain are having the problems. This lets us "aim" the neurofeedback training at these regions. This information also tells us which task is the hardest for the particular person, so we can have them do that task (e.g., listening) while doing neurofeedback.

We can usually predict which type of task is hardest or least fun for a child to do, based on the presence of slow, "sleepy" or "out - of - gear" brain waves. The child and parents usually confirm that. We then know what type of task to focus on during EEG retraining. Some kids (and adults) have what I call "art brains." They get very fine activation when they draw, although they may be very inattentive during listening or other verbal/analytic tasks. These kids I encourage to take "picture notes" in class instead of just writing down words.

QEEG is not intended to be a "stand alone" diagnostic or as a substitute for other medical diagnostics. It is, however, a helpful adjunct which can guide prognosis and intervention. qEEG is best used as an tool to aid in the clinical diagnosis of various dysfunctional states and not as a substitute for clinical judgment and medical opinion. The qEEG should be combined with other medical, psychological and neuropsychological data to best aid the patient.

The sister technology to qEEG is called EEG biofeedback, neurofeedback or neurotherapy. The qEEG provides the "targeting" information. That is, it tells us where and under what conditions (reading, listening, math, etc.) the problem is worst. This analysis allows accurate electrode placement for feedback and suggests the tasks that should be used during therapy. Neurotherapy is EEG feedback-assisted cognitive behavior modification. It couples EEG feedback with the full range of traditional cognitive behavior therapy methods, including imaginal rehearsal, correction of maladaptive thought patterns, and rehearsal of new skills. We commonly utilize intensely activating, challenging tasks during the sessions to enhance brain activation and teach what it feels like to be focused and functional again. The EEG feedback signals the patient when their brain is in fact in a more activated state, indexed by decreased delta and theta brain wave amplitudes, and increased beta and/or alpha amplitudes.

Neurotherapy is no panacea. Like any therapy it works best with people who are motivated, who want to improve, who are experiencing some significant suffering from their symptoms and who are not so discouraged by years of trouble that they don't even want to try any more. In this latter case, depression, helplessness and negative attitudes toward the self - and often others - may have to be treated before the underlying attention, organization or learning problems can really be addressed.

THE SCIENTIFIC BASIS OF qEEG TESTING and NEUROFEEDBACK: References to Publications

Behavioral Medicine Associates, Inc. has many very satisfied patients who can testify that neurotherapy has reduced their symptoms of ADHD, anxiety, depression and brain injury. Memory has been improved, emotional instability has been decreased or eliminated, and executive function has been improved.  

IF QEEG AND NEUROTHERAPY ARE SO GOOD, WHY AREN'T MORE CLINICIANS USING IT?

The instrumentation is expensive and requires serious study and training to use competently. Proper instrumentation has only recently become generally available. Two national organizations to promote and develop this approach have been formed in the last three years. Attendance at the ISNR national conference has grown to 450 this year. More clinicians are using neurotherapy each year. For psychologists and others who did not have extensive graduate training in neurobiology in graduate school, it takes some serious study and work, including supervision,  to become competent in neurotherapy. So the spread is slow, but steady.  

Certification in neurotherapy is advancing and, we believe, necessary so that insurers can choose to reimburse only certified clinicians. A national biofeedback organization, the Biofeedback Certification Institute of America, certifies health care practioners as competent to perform a wide range of types of biofeedback.  The BCIA was established in 1981 to certify practitioners in peripheral (EMG, temperature, GSR) biofeedback techniques and now has certification in EEG biofeedback (neurofeedback) available via tests administered at the major annual conferences of the ISNR and AAPB.

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