A psychologist plans to sweeten people's dreams using their smartphones.
Professor Richard Wiseman expects 10,000 people to take part in an experiment in manipulating dreams. Participants will download a specially designed iPhone app that turns their phone in to a dream factory.
Placed on the bed, the phone can detect when a sleeper is not moving, which signifies the onset of dreaming. It then plays a carefully crafted "soundscape" designed to evoke pleasant scenes such as walking in woods, or lying on a beach.
The idea is that this will influence dreaming, causing dreamers to conjure up situations and experiences inspired by the sounds they are hearing.
At the end of the dream the app sounds a gentle alarm to wake the dreamer, who submits a brief description of the dream to a "dream catcher" database.
The experiment was launched on Tuesday at the Edinburgh International Science Festival.
Prof Wiseman, from the University of Hertfordshire, said: "Getting a good night's sleep and having pleasant dreams boosts people's productivity, and is essential for their psychological and physical well being. Despite this, we know very little about how to influence dreams. This experiment aims to change that."
Prof Wiseman teamed up with app developers YUZA, which created the "Dream:ON" software.
A national survey conducted for the experiment found that 21% of respondents had trouble sleeping and 15% suffered from unpleasant dreams.
The "Dream:ON" app can be downloaded for free from iTunes or via the project site, http://dreamonapp.com