Some Definitions of Common Terms
There are lots of terms that may not be familiar to you.  This is just a beginning.  Please email info@aboutneurofeedback.com if you have suggestions for adding to this list.  It's incomplete, and will always be a work in process.

• Alpha-Theta Training - done eyes closed with soft tones, very deep relaxing training.
• Amplitude of the EEG - This is a measurement in microvolts of the EEG activity for a particular frequency band. Microvolts - millionths of a volt.
• Brain wave frequencies - measured by special EEG amplifiers.  This information, read from the brain with electrodes, has some correlation to brain state.  Click here for more information in the FAQ.
• Beta  - click here, explained in FAQ
• CNS - Central Nervous System - All of the disorders or symptoms listed (click here)  fall under the CNS domain.
• EEG, Changes in the EEG.  Electroencephalograph - Measure of electrical activity of the brain.  To really understand how it's calculated is a fairly complex discussion, more than we can tackle here.  Changes in the EEG essentially mean - that more neurons are doing the same thing at the same time.
• ECT - Electro Convulsive Therapy.  Still commonly used by some psychiatrists, in particular for severe depression.
• Electrodes - click here to see electrodes and a bit about electrode placement.
• Excessively Slow EEG - Usually referring to large amplitude EEG in the 1-10 hz or 1-12 hz range. It's often associated with a dysregulated brain. A "well-organized" EEG should be smaller and faster.
• Excessive Fast EEG - Usually referring to excessive amplitude in the 20-36 hz range, or 22-36 hz.  Sometimes it can include 15-20 hz activity.  This is not considered optimum activity for a well-regulated brain.

• Brain Timing  - Frequency, amplitude, coherence are all measures of brain timing.  When you see changes in the EEG from these measures, these are real measures of physiologic change.  They reflect changes in how groups of neurons fire (produce neurotransmitters) or don't fire.  A full explanation is part of a neurophysiology text book and is well beyond the scope of what we are doing here. There are courses that provide good explanations of the neurophysiological mechanisms of the EEG.
• Bi-Polar Electrode Placement - To get an EEG signal requires 3 electrodes.  A signal, reference, and ground. If the signal and reference are both placed on the head (the reference is not placed on the ears) it's considered a "bi-polar placement. The EEG at both the signal and reference be read by the amplifier and subtracted from each other. The results are displayed as the EEG.
• Interhemispheric training (electrode placement) - Same as Bipolar explanation above, but the site placements are made at homologous sites. That means, you still have 2 electrodes on the head, but they are at C3 and C4, or P3 and P4.
• International 10-20 system for measuring electrodes.
• International 10-10 system for measuring electrodes.
• Monopolar or unipolar placement - To get an EEG signal requires 3 electrodes.  A signal, reference, and ground. If the signal is placed on the head and the reference is placed on the ears, that is considered unipolar or monopolar placement.  The EEG at both sites of the signal and reference electrodes will be read by the amplifier and subtracted from each other.  Since the ear is considered neutral (no EEG in theory), only the EEG results from the signal will be displayed as the EEG.
• Neurotherapy - What’s the right name: Neurofeedback, EEG Biofeedback . . . ? Click here.
• NF - Neurofeedback abbreviation.
• Operant conditioning - click here.
• Protocol - Usually referred to as "where and what to train" with neurofeedback.  For example, what site you place the electrodes at and the frequency you choose is "a protocol." If you change the frequency, it may or may not be considered a new protocol.  If you change the site, it's probably always considered a new protocol.  There are some who don't like the idea of "protocol".  However, most professional clinicians use this concept and word regularly.
• qEEG - A quantitative EEG is a computer analysis of the EEG signal, typically using 19 or more channels of simultaneous EEG recording under specific recording conditions.  This EEG data is compared against a reference database of other “normal” EEGs.  The analysis identifies and highlights variations from the norm. 
• Spectral Display - This refers to a bar display that is calculated using a fast fourier transform.  It's a particular calculation applied to the EEG to measure and display all the frequencies within a segment of the EEG. Since slower parts of the EEG such as delta might occur only 1-3 times per second, it takes at least a half of second to computer an accurate frequency analysis and display it.  So they take 1/2 second to 1 second of data, compute how frequencies are distributed within that time.  It is usually displayed in various types of graphs. Since spectral analysis requires averaging of data, some point out it's not real time, so not as precise a way of proving the brain feedback as using real time filters.  Others note that training on spectral feedback does have training value, through you would probably not want to train only on a spectral calculation. Most neurofeedback software offers faster filters for feedback - and also spectral as a way for clinicians to detect changes.  Some clients like training on it also.
• Unipolar or Monopolar Placement - To get an EEG signal requires 3 electrodes.  A signal, reference, and ground. If the signal is placed on the head and the reference is placed on the ears, that is considered unipolar or monopolar placement.  The EEG at both sites of the signal and reference electrodes will be read by the amplifier and subtracted from each other.  Since the ear is considered neutral (no EEG in theory), only the EEG results from the signal will be displayed as the EEG.