Saw this UC Berkeley study posted on Facebook earlier and clicked through. This is one of those things that shows you a glimpse of the future. Like watching Gattaca or learning about a company like Navigenics.
This is absolutely going to happen as technology continues to advance. Our brains will continue to be studied until they, like DNA, can be decoded.
And yes, decoding brain activity, like DNA, is going to put a serious crimp in the ability for humans to lie successfully.