This is the Future
You’ve got a small device, about the size of a big watch face — one of those chunky watches that they sell at Fossil. We’ll call it a medallion. This is what it has in it: electrodes (possibly: very tiny lasers), a gyroscopic battery that charges up when you move your head, and bluetooth. The edges of the device are porous and the battery gives them a very tiny charge; bone cells, which are piezoelectric, accumulate in the pores, suturing the device into the skull.
You stick this guy in the hole that you made in your head — around your parietal bone, probably, where the squamous border meets the frontal border. There’s a suture there, it’s soft anyway. This spot is roughly over the inferior frontal gyrus, or Broca’s Area. It’s closely associate with speech expression.
Maybe you use a different spot, it doesn’t really matter. You’re trying to find a spot where there’s a lot of variation in neuron expression on purpose.
The electrodes get maps of different neuron expression and dumps them via wireless into a processor that you carry with you; about the size of an iPhone. Maybe thicker, maybe a little bigger, so that you can improve the battery life and processing power. Plus, you wouldn’t actually need a phone in it.
Experiments are necessary; after you’ve first got the medallion installed, you start trying to express different things. Different maps of neurons are expressed on your processor’s face, the way that music on your media player makes those fancy weird designs. This is called the Calibration Period. During this time, you find unique, replicable designs that you can call up repeatedly by remembering what you were trying to express. You tag them until you have a small vocabulary. Maybe ten. Your little processor remembers those patterns, and you use a primitive syntax to arrange them — three pictures of any of your ten, giving you a thousand individual “sentences”. The sentences are associated with commands; any commands you want. “Turn the phone on,” “start the car,” “open google chrome.” Whatever.
Congratulations, you can now telepathically communicate with your environment.
This is unethical, by the way; medical science won’t let you drill a whole in someone’s head just to see if you can wire them to an iPhone. That’s probably why the Chinese or the Koreans will get to it first.