Unfortunately commercial-grade non-invasive EEG headsets can only reliably respond to things like intense emotional changes and the difference between sleep/awake state, but not much more than that. Awhile ago I had some moderate success classifying the difference between a subject watching an emotional short film vs. stand-up comedy. Mostly they are effective at picking up background noise and muscular movement and not much else.

This is based on my experience with the Muse [1] headset, which has 4 electrodes plus a reference electrode. I know there are similar devices with around a dozen or so electrodes, but I can't imagine they're a significant improvement.

So I think we're still a long way off from what you're describing :(

[1] http://www.choosemuse.com