Unfortunately it is difficult to understand without experience and "learning" it. It was completely different from what I expected, but I was going to try anything.
Basically by mounting a few EEG electrodes on your head it can measure 3 types of frequencies(Delta, Gamma and Alpha, although don't quote me on this). These frequencies relate to the "focus", "relaxation" and "cross-talk" functions of the brain that primarily are controlled by the Sensory-Motor Cortex. Most people who have trouble concentrating and functioning probably have difficulty in all these areas.
Once you are hooked up you are expected look at a screen and listen to some music(usually classical), and try to get your frequency responses below some baseline. Basically strengthening them like a muscle. You actually train yourself based on the feedback the sensors are giving you.
I managed to do some reverse engineering and figure out how the brain works to blow the numbers out of the water. Going from far below average to way above in a matter of months changed my life. I even figured out some things the center never tried before. Like significantly increasing the time I try to maintain the baseline, which allowed me get above average results. There was a lot more I figured out, but far to much for a HN post. Feel free to email for more info. I might make a post on it one day.