Many quantitative EEG Databases use Z-scores to measure how deviant the individual is from the normal population, in terms of amplitude/magnitude (often referred to as “power”), coherence, phase measures, and symmetry.&nbsp;<br><br><p><b>Z scores</b></p><p><ul><ul><ul><li>Z = subject value – mean value of the same/ SD of the sample</li><li>Z= probability that the subject value lies within the normal range. 1.96 Z scores is 2 SDs.</li></ul></ul></ul><p style="text-align: center;"><img src="@@PLUGINFILE@@/chap7-z-score.png" alt="" width="273" height="184" role="presentation" class="img-responsive atto_image_button_text-bottom"><br></p><p style="text-align: center;"><br></p><p style="text-align: left;"><b>LORETA</b><br></p><p style="text-align: left;">LORETA stands for Low Resolution Electromagnetic Tomographical Analysis and was developed and published on by Roberto Pascual-Marquis et al. in 1994. LORETA was a way to locate electric activity in the brain based upon multi-channel EEG recordings. LORETA assumed the that, among the infinite set of possibilities of source localization for EEG, the neighboring neurons were simultaneously synchronized with the source defined. The computational task that LORETA undertakes is finding the smoothest of all possible 3D tomographical distributions (a common procedure in generalized signal processing). Tomography is the term used, as it is accurate in the sense that it is used in PET, MRI, and CT scans.<br></p></p>