Database References

Since I will include many examples of qEEG reports in my next post, here is a brief guide to interpreting them. This is a very simplified version, and I will upload the more detailed one in the future. But before even attempting to understand the report, we must discuss common statistic terminology.

Database: Organized collection of data (in this case, brain maps)

Z-score Tables: Tables of data which indicates how many standard deviations an element is away from the mean. Brain map z-scores will display how far away the client's brainwave amplitudes are away from the normal.

Standard Deviation: A measure used to quantify the amount of variation between different elements in a data set. Concerning brain mapping, standard deviations away from the norm will reveal the severity of the problem; more standard deviations away indicates a more severe problem. 

 Interpreting the qEEG - Introduction

My next post will be about the databases used to create qEEG. Each database contains files for "normal brains" in each age bracket. Some also contain norms, or the various forms, of different mental disorders, which allows for a more accurate diagnosis. By running a client's data through the norm database, we can determine how much brainwave deviation there is. The file is converted into a series of colored aerial diagrams of a head. Each different color represents a certain number of standard deviations in the brainwave amplitudes in a particular region. Let's look at some examples. Below is an excerpt from a qEEG that has ran a client's file through the Neuroguide database.

If the patient's brainwave levels were normal, the aerial view would be completely green (0 standard deviations have been deemed green by the spectrum below the diagram). However, the client seems to have Delta levels 6 standard deviations below the norm (dark blue), which may cause anxiety, nervousness, or insomnia. On the other hand, their Theta levels seem to be relatively normal, with only up to 1.5 standard deviations away from the norm in the right-frontal lobe. Running a patient's raw EEG (literally just brainwaves) through the database will help diagnose their mental disorder. Without the qEEG reports, the area of deficiency/type of disorder would not be known, which would lead to very inefficient neurofeedback training.