October 2, 2008 – Smells could influence the emotional content of dreams. This is what a small German study reports in which 15 sleepers were exposed sometimes to a scent of roses, sometimes to a scent of rotten eggs.
Participants exposed to the floral scent said they experienced pleasant emotions during their dream. The opposite effect was observed in the presence of the smell of rotten eggs.
The smells were introduced during the REM phase of sleep – the phase in which dreams occur – for 10 seconds. After a one-minute delay, the participants were woken up, who then had to tell their dream and its emotional content.
Very rarely, participants said they dreamed of a scent. However, this seems to be able to modify the emotional content of the dream.
Previous studies have also shown that certain types of stimuli, such as sound, vibration, and pressure, also have the ability to influence dreams.
However, smell would somehow have a more direct access to dreaming since it is the only sense that does not sleep. In fact, olfactory information continues to flow directly to the limbic system, the seat of memory and emotions. Information from other senses must pass through the thalamus, an area of the brain that is partially inactive when we sleep.
According to researchers at Mannheim University Hospital, this link between smells and dreaming could be used to adopt new therapeutic approaches to help people who have nightmares.
These results were presented at the annual meeting of the American Academy of Otolaryngology1, which was held recently in Chicago.
Claudia Morissette – HealthPassport.net
1. For more information: www.entnet.org/annual_meeting/
