Have you ever been part of a test screening audience? If so, and if you've chatted to other audience members aftewards, you'll know that what people write down on their response forms often has little to do with their evolving opinions and the word of mouth - good or bad - that they'll go on to give. Test screenings are notoriously unreliable. They continue to be used largely because the industry doesn't have a good alternative. But that may be about to change.
"By looking at patterns of oscillation we could tell at which moments a person was particularly engaged. Additionally, we could see whether the correlation occurred across subjects and repeated viewings," says Dr Lucas C Parra, a Professor of Biomedical Engineering in New York. He's talking about the patterns of brainwaves that correspond to a viewing experience. Parra and his colleagues played clips from The Good, The Bad And The Ugly and Hitchcock's Bang! You're Dead at the same time as using EEG technology to monitor the pattern of electrical activity flowing across subjects' scalps. It's a simple method that's a lot more comfortable for the subject than it might sound, and it meant they could watch in real time as brainwaves shifted depending on what was happening in the films.
Using this method, Parra claims, it's possible to identify moments when film viewers are paying particular attention, as well as registering the strength of their interest. This is something that it would be impossible for their subjects to fake in order to try and impress others by, say, seeming coolly detached. It could enable producers to get a direct, easily quantifiable impression of how interesting a film was.
Of course, its immediate attention-grabbing power is not the only thing that can make a film appealing and it's possible that slower, more thoughtful films might not score highly using this method. But for action blockbusters, horror chillers and psychological thrillers, it could be just the ticket.