Lol, its some serious stuff. I wonder how it really works. its prety messed up if that thing can press on my forehead and read what i want it to do...
Your brain basically breaks down signals to frequencies.
The way youd calibrate it is you would say need to set 'look up' the device would 'listen' to your brain as you thought of, 'look up' it would then remember that signal/frequency and everytime it saw/heard that, it would refrence it to a command.
They have this technology but mainly for paraplegics, they use a mouse with a simple 2 dimensional plane (up down left right) and CLICK to browse the web, or it goes through a dictionary with you (like above) and you think of letters and it shows on the screen what it thinks your thinking so people who can no longer speak can communicate with the outside world.
More info in the link below:
http://www.cbsnews.com/stories/2008/10/31/60minutes/main4560940.shtml
It's interesting, but sort of a back route method to "brain control"
I dont believe anything is even close to understanding the human brain, the closest we can do is have a machine remember what signals correspond to what which is really a workaround...