<p>Quantitative EEG analysis (qEEG) refers to signal processing and extraction of features from the EEG signal, in some cases there is a normative group that the individual being surveyed is compared to, and sometimes the data is digitized without a comparative reference.&nbsp;</p><p>In the typical neurotherapy practice, 19 channel EEG is digitized, edited or adjusted to remove extra cerebral artifact, and subjected to spectral analysis using the fast Fourier transform (FFT).&nbsp; There are numerous clinical normative databases for many different medical comparisons; normative databases help to evaluate clinical disorders.&nbsp; The National Library of Medicine’s database has a comprehensive list of normative databases, that can be found by search for “normative database: at: <a href="http://www.ncbi.nlm.nih.gov/sites/entrez" target="_blank">http://www.ncbi.nlm.nih.gov/sites/entrez</a>. In using a normative database, we are comparing a single person to a population of “normal” individuals for comparative purposes. A normative database will not only identify frequencies or metrics in which the patient is not normal, but will also identify the degree of their deviance.&nbsp;</p>