Curing fears during sleep has nothing to do with eliminating nightmares, according to researchers at Northwestern University, although it may be the best time to help people overcome their phobias according to study author Katherina Hauner.
To prove this, Hauner, a post doctoral fellow at the University’s Feinberg School of Medicine conditioned 15 “healthy” volunteers to fear the picture of a specific face by applying small electric shocks to them whenever they viewed it. At the same time the shocks were administered, she also connected the action to a specific scent (such as lemon or mint). In turn, as the patients continued with their conditioning, their fear levels were monitored by the amount of perspiration they exuded as well as with MRIs.
During the next phase of the experiment, researchers exposed the test subjects to the same scents, minus the shocks, while they were in low wave sleep (a time during sleep when scientists believe consilidation of memory occurs).
“While this particular odorant was being presented during slumber, it repeatedly reactivated the memory of the ‘horrifying’ face,” explained Hauner. “However, when we then showed the same image to them after they woke up, we found that their fear responses were measurably lower than they were prior to it was before they slept. Presumably because they had learned not to associate it with the shock.”
The results were the same even when the participants had no memory of anything happening while they were unconscious, dispelling previously held beliefs that people needed to be conscious and aware of their emotional reactions in order to alter them. However, as neuroscientist Daniela Schiller of the Mount Sinai School of Medicine pointed out, this new study “raises hope that pre-existing phobias, as well as post traumatic stress disorders can eventually be ‘cured’ during sleep.”