The research by German scientists was presented at the largest ear, nose and throat meeting in the world during the American Academy of Otolaryngology Annual Meeting in Chicago.
For their study the researchers used specific volatile smells with a negative or a positive smell ("rotten eggs" versus "roses") in order to simulate subjects during sleep.
When they were awakened the subjects' impressions were recorded and it was found that when the odour was unpleasant the dream was predominantly negative, while when the odour was pleasant, nearly all dreams were positive.
According to the researchers information on olfactory function during sleep has only recently become available, and that this is the first valid study that documents the impact of olfactory function on dreams.
They believe their study may also open a potential field of therapeutic intervention with nocturnal olfactory stimulation.
