Horror movie app uses sweat to ramp up terror

The Sensum wrist-mounted sensor and accompanying app measures your galvanic skin response (GSR) while watching videos then sends the sweaty data to your phone via Bluetooth. That generates a graph to show your levels of engagement plus how it compares to others.

The idea is to be able to reward you for getting involved in jumpy horror films, for example. Filmtrip demoed an interactive short film at SXSW back in 2011 in which the audience's GSR and heart rate were measured so that the movie could get gorier the more excited the audience got – now it's working on a full-length sci-fi movie with multiple endings.

The tech will be used to unlock tailor-made soundtracks, characters, special effects and plot twists. Chances are it won't stop at movies either – online comics and video games could become much more interesting if Sensum takes off.