qEEG: The EEG & the “q”
The Electroencephalograph is a device which measures electrical-chemical reactions of neurons across the scalp of the cerebral cortex (outer brain). Tiny cup like sensors captures the signal, which is then amplified by the EEG machine. Some doctors and clinicians use “caps” which look like cloth swimmer’s caps with the leads sewn into them at the precise locations of the International 10-20 System. Whereas some clinicians are more “old school,” still applying each lead one-by-one. Regardless, there are 19 sites which are universally accepted, allowing fellow doctors and clinicians to discuss certain regions and ensure everybody is on the same page.
In the old days, this analog signal, captured from these 19 sites, would be drawn out on rolls of paper, which the doctor would then read and interpret. However, the newer technology converts this analog signal to digital, allowing for the ability to save to the computer, as well as the option to export this data into other software programs for analysis.
The “q” is for the quantitative analysis performed to the raw EEG data collected. Psychologists and Neurotherapist utilize additional software programs to identify areas of the brain that are under or over-activated and look for correlations of these brain patterns that have been documented in psychological/behavioral concerns.
What is measured by the qEEG?
The electrical energy of our brain communicating is also referred to as brainwaves. Neurons release and connect to other neurons. The frequency at which they do this is measured in hertz (cycles/second). There are 4 main categories of brainwaves, which correlate to the observed mental state as follows.
- Delta .5-4 hz (cycles/second) - associated with sleep
- Theta 4-8 hz - dream like state, reflective, creative inward thought
- Alpha 8-12 hz - “in the now” focus, an alert relaxation
- Low Beta 12-15 hz (SMR in a particular region) - mind/body calmness
- Beta 15-20 hz - mental alertness, processing, analytical
- High Beta 20-30+ hz - over-active brain, anxiety, obsessive or racing thoughts, panic, etc…
As you can see, as our brain increases in frequency, our mental state also increases. To complicate matters, every location we examine, of the 19 sites that is, has an assortment of these Delta, Theta, Alpha and Beta brainwaves. The qEEG analysis allows us to see how much or how little each site has at each frequency. This data can then be analyzed in ratios, connectivity, asymmetry and coherence measures (how much each site talks to one another).
This objective account of what our brain’s function becomes a starting point for balancing one’s brain and their life. Our brain is like our engine, it determines how we think, feel and act. A brain that is struggling with too much or too little activity in any region can limit one’s happiness, productivity, and self-esteem. We’ll get into more of this later on, but hopefully this quick brainwave introduction will help.
Medical vs Clinical Focus:
It may be helpful to differentiate the medical and clinical usages of the EEG machine. Medical professionals utilize the raw EEG and look at the squiggly lines on the paper/computer screen. They are looking for biological problems and abnormal waveforms that may be seizure, learning difficulty, or brain injury. While they can examine each channel/site’s activity, there isn’t a way to filter out the different brainwave categories (Delta, Theta, Alpha & Beta) in each line. The raw EEG shows all brainwaves in a single source, which limits analysis of the percentage of each category.
Clinicians, on the other hand, examine the same raw EEG for any abnormal patterns or waveforms, and refer to a medical doctor immediately if there is any concern of a biological imbalance. After ruling out any biological concerns, the Psychologist or Neurotherapist would begin looking for brainwave imbalances, using additional software that allows for not only the Delta, Theta, Alpha and Beta categories, but all the individual frequencies inside of them. Brain maps, or the qEEG database assessments show 30 different frequencies of the brain at all 19 locations, offering countless options for analysis and identifying areas of the brain that are under or over-activated. Thus, the clinical perspective is not competitive, but complementary, offering another angle of understanding brain function.
For example, a medical doctor could sign off on a raw EEG (no biological concerns of the EEG); however, this raw EEG data could then be analyzed using additional software programs and databases, which could identify signature patterns of under/over-activated regions would point to clinical or psychological significance in areas such as ADD/ADHD, depression, anxiety, sleep disturbance, obsessive compulsive tendencies, post-traumatic stress disorder and so on. Therefore, it is possible to not have anything biologically abnormal, yet still have some areas of the cortex that could use a little tweaking or balancing.