You may have heard before about movies that let the audience choose how it progresses, usually through some sort of voting system. But this is something completely new. The BBC have a feature article on a a new film by Alexis Kirke that is directed by the audience’s physiological emotional signals. They will use brain activity, heart rate, muscle tension and skin conductance (sweating) signals to indicate if the film is too boring or too tense, and will then change the scene based on the data they get from those signals.
It should be noted, however, that the best this film can do is measure levels of arousal, and probably not specific emotions like sadness, happiness, or disgust (physiological differentiation of emotions is a whole other can of worms I’d rather not open right this second), and it can’t read people’s thoughts. If scientists could get onto the latter, though, I’d be much obliged – that way they could tell that everyone in row 7 really hates the dude in row 6 talking on his mobile and maybe hook up some sort of in-built shock system into the seats… of course, the film industry probably wouldn’t use the technology for that. They’d use it to find out who has been downloading torrents.
A link to the BBC article, which includes an audio interview with the film’s director: http://www.bbc.co.uk/news/technology-21429437