10-20 Head Chart
A standardized system for electrode placement was developed a long time ago. The 10-20 system uses a specific set of rules for measuring. It finds each site in relation to key landmarks at the front and back of the head and at the ears. Many of the sites are either 10 or 20% distances between the major landmarks.
In neurofeedback, the 10-20 system helps with consistent measurements. Each site allows for recording of information that is more specific to the region of the brain underlying it. Some sites are used for training more commonly than others. C3, Cz and C4 are very commonly used for training, as are F3, Fz, F4, and Pz. Pre-frontal is also often used. Which site is used depends on the clinical model chosen. Some clinicians use models that suggest a few sites are all that is needed. Others may include many sites in their training.
Different clinicians, depending on the model of training they use, may choose very different sites to train on any individual’s head.
There is another option shown on the right that has even more sites called the 10-10 system. As clinicians gain experience, or are using brain maps, they may get more specific about what part of the brain to train. These “in-between” sites then may get used for training.