qEEG: Quantitative Electroencephalography

Man facing a computer screen with yellow skullcap on with black electrodes all over it and a braid of black wires snaking out of the top down the back.

The brain is an electrical organ. qEEG reads the electrical messages neurons pass to other neurons. And so qEEG can provide precise information about brain damage: where it’s located, at what frequencies, how far off the norm, whether any given area or network is over- or underactive, how coherent the lobes are (how well they’re working together as well as independently — it’s a balance normally), and other indicators. This and evoke potentials are the only tests that give this kind of precise information at the neuronal level undetectable by MRI or CT.

qEEG is relatively inexpensive, not invasive, not excessively tiring, causes no pain, and is not used enough.

The Electrodes

qEEG reads the brain’s electrical activity or brainwaves through electrodes pasted on to the scalp. Standard qEEG assessments use the 10-20 system of electrode placement. Like electronics that use a three-prong plug to plug into the electricity in your home, the electrodes need a ground, that is, the third prong of a plug. qEEG uses your ears as the ground.

The procedure is fairly simple. The technician measures your head and chooses a stretchy cap to fit. The cap has all the electrodes built in plus the grounding clips for your ears. The cap is fitted on your head so that the electrodes line up to the correct locations on your scalp.

Wires from the electrodes are gathered together and plugged into a piece of hardware that then feeds the electrical information from your brain into a computer.

The Software

Computer software shows the brainwaves in their raw state. The software contains a database of normal EEG readings, that is, brainwaves from many, many people who were considered a norm for age, gender, etc. were measured then fed into a database. This normative database is used as a comparison to help interpret qEEG readings. The softare then provides a detailed analysis of the brainwaves, including 3D modelling and MRI-like pictures.

The technician starts the software to ascertain how well the electrodes are picking up your brainwaves. The technician uses a large plastic syringe with a blunted fat needle to squeeze electrogel — a gel that conducts the microvolts of your brain’s electricity to the electrodes — into each electrode. As the technician ensures electrogel fills the electrode and makes contact between the scalp and electrode, the corresponding graphic on the computer will turn from red or black to green. This process takes about ten minutes, sometimes less. Bald heads are harder to connect, apparently. Probably because the skin is thicker. Skin acts as an impedance. (If not, we’d probably give each other shocks every time we touched or come near a head.)

The Recording

Once the program shows that there’s good connections with all of the electrodes, the technician will start the recording software, entering your details and then collecting a raw recording. It is seriously cool watching your brainwaves pop up on the computer screen. Eye blinks and muscle contractions will appear on the screen as large spikes.

Muscle contractions are usually from the jaw, but the neck muscles can also cause spikes. Eye blinks and muscle contractions are called “artifacts.” The technician will remove the artifacts. Some software can do it automatically, but a skilled human will do an accurate job.

This video demonstrates manual removal of artifacts — eye blinks and muscle contractions.

Once that is done, the specialist or technician will have you relax completely, instructing you to breathe deeply and regularly, relaxing your jaw so it pretty much hangs open, letting your eyes droop without closing them for the eyes open collection. Eyes open and eyes closed are both recorded for several minutes. Brainwaves change when your eyes close. The trick is to stay relaxed without falling asleep. They’ll know if you are, for your brainwaves will tell them.

Not all specialists can tell if you’ve been using cannabis, but Dr. Lynda Thompson of the ADD Centre can see the telltale signs in the qEEG. Since you won’t know how good the specialist is in reading your brainwaves, don’t bother lying about drug taking or mood. Your brainwaves will reveal the lies. For this reason, it’s important that you have trust in the integrity of the specialist and clinic who’s conducting the qEEG and subsequently drawing up your individual treatment protocol. Trust isn’t only about confidentiality regarding things no specialist can normally see, but also about their ability to discriminate brain injury from depression, for example.

When choosing a clinic or specialist to conduct the qEEG, ascertain their experience and knowledge of how to acquire a good recording. Find out, too, who trained them. The Biofeedback Certification International Alliance accredits specialists. Ensure the ones you choose have the appropriate accreditation. Find an accredited practitioner through their website.

The Results

The qEEG will reveal how your brain is functioning, what areas are snoozing, which are overactive and at which frequency. It will tell the specialist the neurophysiological basis for symptoms after brain injury. It, along with evoke potentials, is the main step to developing a treatment protocol to restore function and health. I’ve posted examples from my qEEGs pre-treatment and after the first 40 sessions of single-electrode brain biofeedback treatment back in 2005 and 2006 (grey-scale printouts) and newer style reporting that you’re more likely to receive, from reassessment in 2015 to decide what next to treat via single-electrode brain biofeedback. To read the full story of what qEEG testing is like, why these examples are a decade apart, and why I wasn’t fully recovered in 2006, see Concussion Is Brain Injury: Treating the Neurons and Me. Click an image to open in a lightbox.


Lynda Thompson, PhD, Michael Thompson MD. The Neurofeedback Book 2nd Edition: An Introduction to Basic Concepts in Applied Psychophysiology. 2nd Edition.

D Corydon Hammond, Jay Gunkelman. The Art of Artifacting. 2011.

Bruce Fisch. Fisch and Spehlmann’s EEG Primer: Basic Principles of Digital and Analog EEG. 3rd Edition. 1999.

LORETA: Low Resolution Electromagnetic Tomography. The KEY Institute for Brain-Mind Research, Zurich.

HBI: Human Brain Indices Database. Bio-Medical Instruments.

iSyncBrain. Korea. Cloud Server EEG normative database. iMediSync.

Jay Gunkelman, QEEG Diplomate, Co-Founder and Chief Science Officer of Brain Science International, has been reading raw EEGs since 1972 and working with qEEG since it was first developed. He’s read 500,000 EEGs and is considered the person to consult with when specialists in EEG are stumped or would like second opinions. He developed a model of 11 EEG phenotypes that have been proven to have genetic links. His Vimeo page has a plethora of educational videos on EEG for those who would like to learn more. Embedded here is his first lecture on returning to the basics of being able to read raw EEG.

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