thedragonbook

I came across this research and now am wondering if we can measure the transition from happiness to unhappiness and vice-versa using brain states? http://newscenter.berkeley.edu/2011/09/22/brain-movies/ I mean, if we can reconstruct a part of a movie from brain states then why not happiness/unhappiness. I understand that different people have different opinion about happiness/unhappiness. But why not *ask* the person being scanned what makes him/her happy/unhappy and based on that map the brain states to happiness/unhappiness?