What is a quantitative electroencephalogram (QEEG)?
Starting in the 1970s it became possible to store the EEG signals on computer media for later analysis. As computers and electronic amplifiers became smaller and faster, and as mathematical methods developed, it has become possible to store 19 or more channels of EEG data on a laptop computer using an amplifier the size of hardback book. Often the sensors are attached to the inner surface of a cloth or mesh cap. The caps come in various sizes so that the sensors will be accurately placed on any size head. The computer is capable of recognizing many more and subtle patterns among the brain waves in various locations than the eye can possibly see. These patterns are then graphically displayed as colored brain maps, graphs, and charts. Despite the impressive ability to detect subtle significant patterns, the raw EEG must always be analyzed by a trained eye in order to avoid misinterpretation or ambiguity in the QEEG. A very special feature of modern QEEG is that all the data from a client
