Imagine watching a movie where you can change the ending because you don't like the director's cut. Well, it's now a possibility.

A UK researcher has made a short film with millions of different outcomes which can be manipulated by the brain signals of the audience.

This is not just any mobile cinema, and the movie these people are watching, isn't just any movie. One member of this audience is seeing if they can manipulate what happens in the film.

The film called The Moment is the brainchild of Nottingham University researcher Richard Ramchurn who is literally using the brain signals from a member of the audience to dictate what happens. Student Hulda Cheng is wearing an EEG headset which is monitoring her reactions to what she's seeing.

The sensor can't fathom what you're thinking, but it can tell whether your attention span is increasing or decreasing and it's the change in attention span which signals a shot change in the film. Effectively, it's offering you a change of scene when it thinks you're getting bored.

The film is a dark thriller set in the near future when brain computer interfaces are more technically advanced and everyone cannot help but be connected to each other.

Cheng and her friends are students from Northeastern University in the US and they're particularly interested in seeing whether she's conscious of being able to dictate changes in the film. When she's wearing the headset it sends wireless signals to Ramchurn's laptop computer. The laptop contains software which can alter the editing of the scenes and the sounds.

RICHARD RAMCHURN, RESEARCHER NOTTINGHAM UNIVERSITY "There's billions of different combinations of this film, it's twenty-four minutes long and each scene splits off, there's multiple variations of each scene, but also each second can be different. Each second there's a possible version of the film, so it's pretty much infinite variations of the film. What's really interesting is how people watching it still get the narrative, they get the meaning behind the film."

Ramchurn has converted a caravan into a plushly upholstered mini-cinema and he's showing his film to small audiences at documentary festivals across the UK.

HULDA CHENG PARTICIPANT "Like in the beginning when they first put the mask on, I was kind of scared and I tried to have that stop and there just kept being more of it, so, I'm not sure why it didn't change, but every time I felt something, like sometimes I'd be like, oh I want it to be this way and it didn't do it."

Ramchurn says it works best subconsciously. He says people who consciously try to dictate changes will end up with a choppy film which doesn't make sense. But whether any meaningful research can be gathered this way and whether the EEG is detecting and tracking the right brain signals remains to be seen.