<p></p><p></p><p>The definition of quantitative EEG is very broad and encompasses all quantified EEG in term of phase, coherence, power and/or other brain-computer interfaces. However, for the sake of simplicity, we will refer to the quantitative EEG as a test comparing the electroencephalography of the individual (EEG) to a normative database, which is a database of “normal” people within the clients age range who are physiologically and psychologically healthy. The individual is assessed from the perspective of how many standard deviations from the norm their EEG data occurs within.&nbsp; This creates what we know as a “brain map.” Maps are taken using standard deviations from the norm by way of or power output (measured in microvolts squared or pure microvolts).&nbsp;&nbsp;&nbsp;&nbsp;</p><p>When recording, traditionally in the field of neurotherapy, the international 10-20 system for electrode placement is used (a 19-channel cap) and electrode impedance of less than five kilo ohms is used. Activity at the functional regions of the brain, including Brodmann areas, can be incorporated into the findings with the use of Low Resolution Brain Electromagnetic Tomography (LORETA) software.</p><h3>Low Resolution Tomographical Analysis Image</h3><p><img src="@@PLUGINFILE@@/LORETA%20Imagery.png" alt="LORETA Imagery" width="928" height="653" class="img-responsive atto_image_button_left"><br></p><p>Typically, an EEG is recorded in two conditions: eyes open and eyes closed. A clinician can use as many or as few databases as they wish, each database has its own high points and short comings. &nbsp;Depending on the database, data can be understood from a variety of different montages. Some of the more well-known databases include: Neuroguide, HBI, BrainDx, iSyncBrain, and more.&nbsp;<i></i></p><p>The images created by quantitative EEGs will show an overall view of the client’s brain waves (EEG) relative to a normative database of other people their own age. Colors are often used to indicate how many standard deviations they are from the normal population. Also (often) shown are connectivity issues in coherence (the stability of the phase relationship between different sites in the brain) and phase lag (a measure of how waveforms come into and out of synchronization).</p><p>Quantitative databases usually give an overall view of the individual’s data from a Fast Fourier Transform (FFT) perspective. &nbsp;Absolute Power is the total voltage, or energy, that the brain is emitting, measured in microvolts squared in disparate frequencies. Relative Power<b>&nbsp;</b>is<b>&nbsp;</b>a measure of clients’ EEGs, viewed in relation to their absolute power profile, used to determine what may be deviant, in relative terms. Magnitude is measured in pure microvolts.</p><p>A measure of clients’ EEGs, viewed in relation to their absolute power profile, is used to determine what may be deviant, in relative terms.&nbsp;&nbsp;<span style="font-size: 1rem;">When reading a Z-score map, 1.64 standard deviations is considered the threshold of clinical significance.</span></p><h3><span>Interpreting the Data</span></h3><p>The summary pages of many QEEG reports give an overall view of the goings on from a neurophysiological perspective. Each column contains the activity for one bandwidth (delta, theta and so on). Each row contains a separate metric. The colors indicate how many standard deviations, or Z-scores, the client is from the normal population. The thickness of the lines also depicts deviance in Z-score measures. Absolute Power is the total voltage, or energy, that the brain is emitting, measured in disparate frequencies and typically portrayed after processed via a “normative database.” Relative Power<b>&nbsp;</b>is<b>&nbsp;</b>a measure of clients’ EEGs, viewed in relation to their absolute power profile, used to determine what may be deviant, in relative terms.&nbsp;</p><p>Coherence is<b>&nbsp;</b>the stability of phase relationship between any two areas of the brain. Two areas are said to be coherent if they have constant respective relative phase. Coherence in excess is hypercoherence; coherence in deficiency is hypocoherence. Phase is any one point or portion in a recurring series of changes, as in the changes of motion of one of the particles constituting a wave or vibration; the metrics of phase are very similar to coherence and will be discussed further in the document. In the articles folder, you will find an entire report from the Neuroguide Quantitative Database, as well as an entire report from the iSyncBrain Database.</p><p><a name="_Toc35418096" style="color: rgb(55, 71, 79); font-family: &quot;Open Sans&quot;; font-size: 2.143rem; background-color: rgb(255, 255, 255);">A summary Page from a Quantitative Database (NeuroGuide)</a><br></p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Summary%20Map.png" alt="Summary Map" width="716" height="955" style="font-size: 1rem;"></p><p></p><p></p><h2><a name="_Toc35418097">A summary page from a Quantitative Database (SKIL)</a></h2><p style="text-align: center;"><img src="@@PLUGINFILE@@/SKIL%20Summary%20Map.png" alt="SKIL Summary Map" width="729" height="453" style="font-size: 1rem;"></p><p></p><h2><a name="_Toc35418098">A Summary Page of Individual Hz bins in SKIL</a></h2><p style="text-align: center;"><img src="@@PLUGINFILE@@/Individual%20Hz%20Bins.png" alt="SKIL Individual Hz Bins" width="638" height="332" style="font-size: 1rem;"></p><p></p><p style="text-align: center;"><br></p><p></p>