People often ask how it is that neurofeedback can detect brainwaves in order to train them. After all, the electricity in the brain is a faint signal and must make it through the skull to be located and measured.

Scientists have found several ways to measure. The oldest and most common are electrodes, as seen in this photo.  They are attached with a hypoallergenic paste that helps conduct the electrical signal.  My preference is the type with blue, disposable tips, but I’ve shown in the image what are called cup electrodes for comparison, and there are also flat electrodes about the same size as the cup electrodes.  I use electrodes almost all the time in my office, because the conductive paste can be cleaned up with soap and water or, as I use, rubbing alcohol.  The advantage of using electrodes is that after doing brain training, a person can leave the office and go on to another activity with no visible signs of having done brain training. This, I believe is a huge advantage for people trying to fit neurofeedback into a busy day.

People often use caps for measurement, as well.  One of my caps is shown in this second image. It fits snugly on the head, and the wires detect signal through a gel that is inserted into the white connectors. There also are caps that connect snugly under the chin and use saline for electrical conduction (not shown).  The advantage of caps is that they are fast to use when doing a brain map and measuring electrical activity at 20 sites on the head. The disadvantage is that the gel does not wash out, so one usually prefers to go home and shampoo. Although some, especially home trainers, prefer the cap because it does not require knowing how to locate training sites on the scalp, it tends to be messier and less comfortable. In addition, some children find the cap intimidating. I have a cap on hand for those who prefer it.