Can certain smells help you tackle your fears? US researchers suggest that it’s a possibility, if you’re sleeping that is.
In the study, people were trained to associate two different images that were linked to smells, with fear. They were then exposed to one of those smells while they slept, and upon awakening, were less frightened of the image that was linked to that smell. The Nature Neuroscience study was acclaimed by an expert from the United Kingdom, and said, ” it could help treat phobias and perhaps even post-traumatic stress disorders.”
“People with phobias are already commonly treated with “gradual exposure” therapy while they are awake, where they are exposed to the thing they are frightened of in incremental degrees.” It is a possibility that therapy to achieve the same goal could be used while we are in “slow-wave, or deep sleep.” Deep sleep is the period of sleep where memories, specifically those that are linked to emotions are supposed to be processed.
During the study, researchers showed 15 different healthy people pictures of two different faces, and were given a mild electric shock simultaneously.” Also, they were exposed to different smells, including lemon, mint, clove, wood, or new trainers. They were then taken into a sleep lab. While they were in slow-wave sleep they were exposed to a smell linked to one of the faces they had been shown. Later, when they were awake, they were shown both faces – without the scents or shocks.”
“They showed less fear when shown the face linked to the scent they had smelt while asleep than when shown the other face. Their response was measured through the amount of sweat on the skin and fMRI (functional magnetic resonance imaging) brain scans. These showed changes in the areas linked to memory, such as the hippocampus, and in patterns of brain activity in regions associated with emotion, such as the amygdala. People were in slow-wave sleep for between five and 40 minutes, and the effect was strongest for those who slept for longest.”
Dr Katherina Hauner, of the Northwestern University Feinberg School of Medicine, Chicago, who led the study, said: “It’s a novel finding. We showed a small but significant decrease in fear. “If it can be extended to pre-existing fear, the bigger picture is that, perhaps, the treatment of phobias can be enhanced during sleep. phobias would be the most obvious area to pursue, as cues tended to be relatively simple, compared with the more complex post-traumatic stress disorder (PTSD). And she said much more research was needed to fully understand the effects this therapy could have. This was just one day. We really need to see if it can last weeks, months or years.
Jennifer Wild, consultant clinical psychologist at the King’s College London Institute of Psychiatry, said: “The sleep study is excellent and has implications for treating phobias and stress disorders, such as post-traumatic stress, where there are a whole range of cues. “Many people who have survived traumatic events, such as fires or road traffic accidents, have a physiological fear response to triggers of their memories. Triggers often include smells, such as smoke, petrol, antiseptic smells and alcohol. Infusing these smells during periods of slow-wave sleep could help to extinguish the fear response.” Dr Wild added, “that the theory could perhaps be extended by exposing people to subtle sounds linked to phobias or traumatic memories during their sleep.”