Memories of Fear May be Overcome During Sleep

Memories of fear may like fear of being bitten by a snake or the fear or dying may be overcome during one's sleep, according to the Washington Post.

Scientists at Northwestern University say they have lowered levels of fear in people by using certain odors to trigger and rechannel frightening memories into harmless ones during a deep slumber. "Sleep sort of stamps memories in more strongly," said neurologist Jay Gottfried, senior author of the study, which was scheduled to be published online Sunday by the journal Nature Neuroscience. "That's when a lot of memory formation can take place."

The researchers first created a fear of a certain face in their subjects by using conditioning - making them link a face and an odor in their minds with a painful electric shock. After some trials, the participants became afraid of the face, and the smell acted as a cue associated with that face.

The researchers then used the smell to trigger fear memories during sleep as a way to enable patients to adjust without the stress of conscious terror.

Gottfried and his colleagues have not attempted this on preexisting fears, but theoretically it could be done - by creating a connection between a phobia and a distinct odor. He said the first type of patients who could be helped by this process would be those who already have an odor associated with their fear - for example, the smell of gunpowder.

"From a clinical perspective, this can be a new approach to try and treat stressful or traumatic memories," Gottfried said. He said that fear, a type of emotional memory, is often learned at a young age from experience or observation. A child who was bitten by a dog grows up afraid of dogs, but so does a child who sees his father attacked by one.