What is a qEEG?

Every student who enters The Hope School undergoes a holistic evaluation, including a proprietary neurodevelopmental profile and a qEEG brain map. These pieces of information are crucial as we design a student's program and measuring their growth.

A student during a qEEG analysis

What is a qEEG?

The qEEG stands for Quantitative Electroencephalogram. It is a diagnostic tool that measures electrical activity in the form of brain wave patterns. It provides vital information in terms of the brain’s current state of balance and overall communication patterns within the brain.

Sample qEEG

Frequencies Measured

The qEEG measures the brain’s current state of balance and overall communication patterns at the electrical frequencies of Delta, Theta, Alpha, Beta, and High Beta.

Delta frequencies (1-4 HZ) are produced during sleep are widespread in the frontal central region. Delta is necessary for sleep and stillness.

Theta frequencies (4-8 HZ) are associated with selective attention, retrieving newly learned

information, and preceding sleep. Theta aids creativity and problem solving.

Alpha frequencies (8-12 HZ) appear in the posterior when the eyes are closed. It is associated with idling and resting, not sleep. Excessive Alpha is associated with decreased cognitive performance and quieted excitation and responsiveness. Alpha can be restorative and restful.

Beta frequencies (13-30 HZ) are primarily considered to be a cognitive frequency range. Beta conducts the rational, reasoning aspect of cognitive solutions.


Color Coding

The Absolute Power and Relative Power colored brain maps are based on standard deviations above and below the norm, and color coded per the chart above accordingly. One standard deviation (SD) above the norm is yellow, two SD above the norm is orange, and three SD is red. ‘0’ is the mean within the green and light green range. One SD below the norm is light blue, two SD below is darker blue, and three SD is darkest blue.

Amplitude Asymmetry, Coherence, and Phase Lag are displayed as maps. The small dots on the maps represent the areas where the electrodes gathered the data. The thin blue line represents one SD below the norm and gets thickest up to three SD below the norm. The thin red represents one SD above the norm and gets thickest at three SD above the norm. No lines mean within normal range.



Absolute Power: How much brainpower is available?

Absolute Power reflects the actual microvolts recorded at each of the sites. The amplitude or voltage the brain produces is measured at each of the sites, and aids in determining whether enough brainpower within a particular frequency range is present at each recording site. This can be too much or too little.

Relative Power: Who’s in charge here?

The Relative Power is the distributed total amount of power at each site, and measurement aids in determining whether a particular frequency is overpowering other vital brain frequencies or if the power is low.

Amplitude Asymmetry: The brain’s balancing act.

Asymmetry scores reveal to us whether the brain waves between the various parts of the brain are balanced. Excessive activity may indicate an over-firing of brain cells. Insufficient activity may suggest brain cells are not firing sufficiently to maintain proper brain function. Both will lead to inefficient brain function.

Coherence: How efficient is my brain’s ability to communicate with itself?

In order for us to understand the complexity of the world and to make and execute decisions the different parts of the brain must share information. Coherence is one of the measurements on how well the brain is able to perform this inner self-talk. This measure gives us an indication of how efficiently our brain is working to connect and disconnect different parts of it to accomplish a particular task.

Excessive coherence tends to indicate two or more areas of the brain are “overly connected or locked together”. That is, the brain has become overly dependent on those centers and is not efficiently processing and executing information. This tends to result in poor day-to-day performance. Deficient coherence signified a brain is not able to efficiently connect cortical areas to perform specific tasks.

If coherence is extremely high, measured with Z scores, there is limited regional communication, division of labor, connectivity, and regional cooperation. If coherence is extremely low, measured with Z scores, there is limited to no communication occurring between regions.

Phase Lag: Is the brain’s electrical energy moving at optimal speed for optimal performance?

Many of the brain’s functions are timed events, the energy from one part of the brain arriving at another area at just the right moment to perform a specific task. The QEEG measurement is called phase. Excessive phase statistics mean the signals arrive too early; deficient, too late. In either case, the brain is not able to do its job with peak efficiency.


Types of Mapping

Linked Ears Mapping

Linked ears mapping shows an average across the head and represents global effects. Since medication doesn’t just influence one area of the brain, the effect of medication is seen in linked ears mapping.

Linked Ears qEEG

Laplacian Mapping

Laplacian mapping gives an overview of the brain without a medication effect. This is

accomplished by a localized weighted average of the nearest four electrode sites, thereby

factoring out a medication effect which is a globalized phenomenon.

Laplacian qEEG

How reliable is a qEEG?

Average qEEG Reliability

Linked Ears: 0.98 (SH)

Linked Ears: 0.98 (TRT)

Laplacian: 0.98 (SH)

Laplacian: 0.96 (TRT)


Next Steps

If you are interested in learning more about a qEEG and creating an individualized program to help your student overcome social, emotional, and relational challenges? Contact us!

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