The human brain is similar to a radio transmitter, but low freq range (0.5 to about 40 Hz usable) and very low amplitude. I've attached a link to a YouTube I did that shows electrical waveforms from each of 19 measured brain areas. It is then converted to a datatable, then to 3-D images of electrical networks in the brain, associated with cognitive functions....similar to the bandscope on the Flex, but you can actually discern ideas about brain functioning from the brainwave patterns...so, I keep trying to read more into the freq display on the Flex. Still, interesting comparison, if you're interested.
YouTube link is: https://youtu.be/N4Ts2gz1neg