A qEEG (Quantitative Electro-Encephalogram), provides a detailed map of how your brain networks are communicating.
Unlike simple comparison‑based qEEG reports—which match your data to a database and stop there—Dr. Sarah Prinsloo brings deep expertise in clinical neuromodulation, oncology‑adjacent symptom science, and brain‑network interpretation.
Her approach integrates qEEG findings with sensory, cognitive, emotional, and functional data to understand how multiple systems interact. This holistic interpretation allows us to identify meaningful patterns that would be missed by surface‑level comparison alone.
What Are Brainwaves? The Longer Story
Every time a brain cell fires in a synapse there is a tiny electrical impulse, far too small to be read by any standard equipment. However, because our brain is composed of billions of neurons firing hundreds of times per second and each is in communication with perhaps a thousand others, organized patterns are strong enough to be detected, even outside the head.
With an electrode on the scalp, we can measure this complex signal and then break the waveform down into different frequencies, known to be associated with different kinds of activities:
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Delta Waves (0.5 - 4 Hz): The slowest waves are associated with deep, dreamless sleep, physical healing, and immune system restoration.
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Theta Waves (4 - 8 Hz): Present during light sleep, deep meditation, hypnosis, and the "twilight" state of drowsiness or daydreaming.
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Alpha Waves (8 - 12 Hz): Occur during a calm, relaxed, but alert state, often when your eyes are closed or you are quietly reflecting. They are associated with reduced stress, daydreaming, and creative visualization.
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Beta Waves (12 - 30 Hz): The dominant rhythm during most of our conscious, waking hours. They are associated with active thinking, focused attention, problem-solving, and alertness.
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Gamma Waves (30 - 100 Hz): The fastest oscillations, associated with peak performance, hyper-focus, advanced cognitive functioning, and heightened perception. They play a major role in integrating information across different areas of the brain.
Raw EEG output
Example qEEG output
So What Is a qEEG?
A basic EEG is a measurement of the electrical impulses that can be detected with electrodes placed on the scalp. These electrical signals in their raw form are complex waveforms varying constantly over the head.
A Quantitative EEG (qEEG) is the name for analyzing those raw signals. The analysis has many possibilities depending on the knowledge and experience of the the person doing the analysis.
First the raw waveform is split into different frequency bands for each location on the head. By comparing this to a large population it is possible to identify abnormal patterns. This technology is decades old, and abnormal patterns are known for many psychiatric disorders such as anxiety, ADHD and depression.
More advanced analysis can infer activity deeper in the brain and give insights into how the larger brain networks are operating.
After this, even more advanced interpretation is obtained by integrating qEEG findings with sensory, cognitive, emotional, and functional data to understand how multiple systems interact. We believe this integrated approach gives the best results for patients rather than a simply applying standard protocols to identified brain patterns.
Commonly Asked Questions
Is the qEEG done in person?
Yes the raw data acquisition for the qEEG must be done with a personal visit.
Where can I do the EEG?
While our practice is based in Houston, we support patients outside the Houston area by working with other clinics near you that have the right expertise to gather the raw data for us.
What does the visit involve?
During a 30 to 60-minute session, you will wear a comfortable elastic cap fitted with small sensors. A clinician applies a water-soluble conductive gel to your scalp to help the measurement. Your brain's natural electrical activity is measured completely painlessly while you sit in a still, calm, relaxed state.
Content reviewed by: Dr Sarah Prinsloo, PhD
Last Updated: July 2026