Well you’ll need three states which are easily translated to the commands.
The more channels you have, the easier it is tor recognise any specific configuration of brainwaves.
It’s not like thoughts are as easy to pinpoint as spatial coordinates. You don’t really decide what your specific brainwave output will be when you focus on thinking “up”. It will be a combination of different brain waves, and the more accurately you can measure that, the easier it is for the computer to pick up when you’re thinking “up”.
Try playing a tune with just three tones available to you, it’d be hard.
The technology isn’t new, but the resolution sort of is.
Hell they used the tech in a House episode in like, 2009.
What do you mean “if you can’t control them”? The channels are how many bands you’re reading, and they are using quite fancy computers to do the reading. What’s there to control? BCI is just a fancier interface than a keyboard, it’s still only one-way, so I don’t understand what you mean by “control” in this context.