Smelling roses may give you pleasant dreams. On the other hand, smell something stinky, and your dreams might be closer to nightmares.

In a small study in Germany, researchers gave 15 women a whiff of roses or of rotten eggs or a nonscented whiff after they enter REM sleep, the stage at which dreams occur. They waited one minute before waking the women, who reported that roses led to dreams with positive emotional tone. The rotten eggs, however, had a negative effect. The dreams were not about tastes or smells, said lead author Boris Stuck of the University Hospital Mannheim, who announced the findings in Chicago at a September meeting of the American Academy of Otolaryngology-Head and Neck Surgery. “This study shows that odors are processed nonconsciously, which is for the most part how we perceive them in everyday life,” says Johan Lundstrom of the Monell Chemical Senses Center In Philadelphia. “Putting a few flowers in your bedroom will give you a more joyful Life.”