Can you imagine going to a movie and having the power to determine how its plot will play out – just by thinking about it? A creative festival in Hong Kong proved this has now become a reality.

"Mind-controlled movies" are just one of the highlights of the Spark festival in Hong Kong, a three-day event organized by the British Council that celebrates creativity in science and the arts.

The mind-controlled movies are the creation of Richard Ramchurn, a graduate of the University of Nottingham in the UK and a collaborator at the festival. Using electroencephalography devices that detect electrical activity in the brain, he has adopted the technology to detect how much attention a user is paying to something.

At the festival, each small screening of "The Moment," a 27-minute feature directed by Ramchurn, will see one audience member don an electroencephalogram (EEG) device. Scenes from the film will change in accordance to the brain activity detected.

Different people will see different versions.

The mind affects the movie, and the movie affects the mind.

The movie explores the concept of how the very technology Ramchurn is creating could go wrong in a dystopian future where brain-computer interfaces are a normal part of society.

Someone could imagine anything – including their dreams – and it would appear on screens instantly.