There's a "non-invasive" brain-computer interface on the market. It's a little less ambitious; targeted towards people who practice meditation. https://en.wikipedia.org/wiki/Muse_(headband)
Trying to read brain signals from a skin-based EEG device is like trying to listen in on a conversation being had inside a packed sports stadium while you fly over it in a helicopter.
Anybody know if it works? Could be cool if I could meditate "good" or "not good" in order to turn a light on and off, or turn on my cat feeder or whatever lol
However, the cool thing about Muse, IMO, is that it's cheap, comfortable (moreso than the Emotiv), gives reasonable signal quality, and has a free SDK for developers. Brain-connecting devices even if they just use EEG open up a lot of doors for interesting products. Assisting in meditation is a great idea, but there's got to be a lot of good BCI ideas that we probably just haven't thought of yet.
It's a very bare-bones EEG system: the Muse has 4 channels and a few references; EMOTIV has either 5 or 14. The slick part is that they use "dry" electrodes, which do not need to be filled with a conductive gel before use. The signal from wet electrodes is still a bit better (less noise, etc), but the gel is fairly gross to have in your hair.