A smell of rotten eggs had the opposite effect of the 15 women sleepers, the German scientists found.
They said a Chicago found that the American Academy of Otolaryngology they now plan to study people who suffer from nightmares.
It is possible that exposure to odors may help the brand more pleasant dreams, believe that Professor Boris Jam and his team at the University Hospital of Mannheim.
They waited until their subjects have entered the stage of REM sleep, the stage at which most dreams occur, and then exposed to a high dose of smelly air for 10 seconds before wake-up a minute later.
The volunteers then were questioned about the contents of his dreams and asked how he felt.
Women almost never dreamed of sleeping smell something. However, the emotional tone of the dream changed depending on the stimulus.
Previous research has shown that other types of stimulation, such as sound, vibration or pressure, can influence the content and emotional tone of dreams.
Dr Irshaad Ebrahim of The Dream Center in London said: “The relationship between external stimuli and dream is something that we are all aware at some level.
“This research is an initial step in the direction towards clarifying these questions and may well lead to therapeutic benefit.”
Professor Tim Jacob, an expert on smell and taste at the University of Cardiff, said: “The smell is the only way not to” sleep “. The information continues to reach the brain’s limbic system, and that includes the hippocampus, or area of memory and the amygdala, that is involved in emotional response.
“Other ways have to go through the” gate “of the thalamus, which was closed when we sleep.”