A fragrant dream will help drive away your fear

Sleep helps reset the brain and calm our emotions. As it turns out, it can do even more. When a sleeping person is exposed to scents they associate with bad memories, they are likely to overcome the fear those memories evoke. Previous research has shown that sleep in general helps eliminate anxiety. However, until now, there has been little focus on how this effect can be achieved using aromatherapy.

Face shots and electric shocks

Researchers from Northwestern University in Illinois, Katherina Hauner and Jay Gottfried, conducted an experiment to prove that a scent released during sleep can eliminate fear . To do this, they presented volunteers with four pictures of faces and a palette of harmless scents, such as peppermint. When the participants saw one face, they received a painful electric shock. The researchers then measured the amount of energy conducted through the volunteers' skin, a measure that increases when anxiety occurs because sweat is a good conductor. The Americans found that this parameter jumped whenever the participants saw a face associated with fear.

Half of the subjects were asleep, half were awake

Half the group went to sleep. Varying amounts of the scent, presented with a "painful" face, were sprayed into the rooms. The next day, these volunteers were less afraid of the face. Those exposed to the highest doses of the scent were the least afraid . Brain scans confirmed this connection. Activity in brain regions associated with fear and memory decreased when the subjects were exposed to the scent during sleep. The rest of the group remained awake while being "attacked" with the scent associated with the "unpleasant" face. Unlike the sleeping group, the greater the amount of scent, the more fearful they experienced. The question now arises as to why the dream separates the fear from the image, rather than strengthening it. Hauner suggests that a clue may lie in the reports of awakened individuals. They indicated that they saw the face in their minds whenever they smelled the fragrance.

Post-traumatic stress therapy

The technique described could aid in the treatment of post-traumatic stress disorder. Images from traumatic experiences could be associated with a scent and then used during sleep. The next step, the researchers plan to take, is to determine during which sleep phase this effect occurs—REM or slow-wave sleep.