so that's good news as that is what I intend to do, that's where my big ones are - accept I may have to cut my hair very short [crew-cut it] - or shave the back of my head so there is no hair causing impedance to the scalp when zapping.
would be interesting to know which head areas you have applied zapping to, would you care to elaborate more?
I'm aware of the white effect, I had that years ago and quickly moved the zapper to a different spot and I believe if I'm correct, that current cannot pass though bone, then the brain should be relatively protected!