<p>At one time in the history of the field, there was a debate as to whether single channel was better than full 19-channel, and vice versa. The difference is the difference in training one to four channel locations, as opposed to training with 19 active electrodes. One is not better than the other, and the question to ask is: is it preferable to train the entire brain (based on the client’s presentation and EEG brainmap) or is it preferable to train single channels? There are many single channel amplifiers&nbsp; on the market.<br></p>