This would take a specialized organ not only capable of generating large amounts of electrical current in various frequencies, but able to survive that current without burning up. This will not ever actually happen, and is perhaps best left to the willing suspension of disbelief.
If you must have this person have a debatable, organic reason they can do this, then the organ need not necessarily be in the brain, but will likely not be very pretty wherever it shows up. It will consume massive amounts of energy during use, making the character weak and hungry frequently. During use, it will probably be quite painful, due to involvement of the surrounding nervous system and heat generation. And in all likelihood, this person has a long list of other problems due to the state of his/her DNA; this isn't evolution, it's a mutation, and in real life this can get weird.
Seriously I'd just hand wave this.