Study: Smokers can learn to dislike cigarettes while sleeping

A study claims that smokers can be taught to dislike cigarettes while they are sleeping.

Bad smells during sleep may teach smokers to dislike cigarettes and help them cut back, a new study hints.

Smokers who were exposed to the smell of cigarettes along with an unpleasant odor during a single night of sleep smoked less for days afterward, the researchers found.

This study shows that "sleep learning can influence later wake behavior," says Anat Arzi. She's a PhD student at the Weizmann Institute of Science in Rehovot, Israel.

She presented the study at the Society for Neuroscience 2014 Annual Meeting in Washington, D.C.

Subliminal Messages

"This research stems from recent findings suggesting that novel associations can be learned during human sleep and retrieved upon awakening," Arzi said during a media briefing.

The researchers chose this method because the brain’s reward system, which is activated during addictive behavior, shares traits with the olfactory system, or sense of smell.

The study involved 76 adult smokers who wanted to quit. During 1 night in the sleep lab, they were exposed to cigarette smells and the smell of rotten fish or rotten eggs during light sleep (known as stage 2 sleep) or during "rapid eye movement" (REM) sleep, when people tend to dream. The odors didn't wake up the participants, Arzi said.

The experiment was also done while the smokers were awake. 

They kept a diary of how many cigarettes they smoked for 7 days before and 7 days after the experiment.

The linking of the cigarette smell to the rotten food smell is called aversive conditioning. The smokers who had aversive conditioning during stage 2 sleep reduced smoking by 34% in the following week. When conditioning was done during REM sleep, they cut back on smoking by 12%.

"The reduction in smoking was significantly larger and longer-lasting following conditioning during stage 2 sleep in comparison to REM sleep," Arzi said.

Aversive conditioning while smokers were awake did not lessensmoking.

"We know that behavioral approaches can help treat nicotine addiction, but none have been remarkably successful," Arzi said in a conference statement.

More study is needed to figure out whether the tactic could work as a quit-smoking aid and a potential treatment for addiction in general, she said during the briefing.

Useful Tool

Marina Picciotto, PhD, from Yale University, said the findings "could be a very useful tool to both motivate and assist people in quitting who might not otherwise have even thought about quitting. This study used smokers, but you could imagine that this could be applied to any addiction."

"We don't know yet from this early study how long the effect lasts and how useful it will be to actually induce quitting, but … the potential as a treatment is there," Picciotto said.

Read more here

Phobias can be treated during sleep

A study claims that fears and phobias can be treated while people are sleeping.

Tallying sleep's benefits can seem as endless as counting sheep. Now, researchers say they might have found another benefit of sleep — it may be a good time to calm fears.

A fear was reduced in people by repeatedly exposing them to the fear memory during sleep, according to a study published online Sunday in the journal Nature Neuroscience.

"It's a novel finding," says Katherina Hauner, the study's lead author. "We showed a small but significant decrease in fear. The bigger picture is that, perhaps, the treatment of phobias can be enhanced during sleep." Hauner conducted the research when she was a postdoctoral fellow in neurology at the Northwestern University Feinberg School of Medicine in Chicago.

The study included 15 healthy young adults who received mild electric shocks while viewing two faces. They were exposed to an odor when seeing each face and getting a shock. In doing so, the face and odor were associated with fear. When a subject was sleeping, an odor was continuously presented but without the associated faces and shocks. When the subjects woke up, they were shown both faces. Their fear reactions were lower for the face linked to the odor they smelled during their rest.

There may be an advantage to adding a nighttime component to exposure therapy, a treatment for phobias and post-traumatic stress disorder, says Hauner, assistant director of the Cognitive Neuroscience Laboratory at the Rehabilitation Institute of Chicago.

Exposure therapy involves exposing a patient to a feared object or situation without danger to reduce anxiety. A therapist usually uses this technique with a patient during the day.

It may be helpful for patients if they can experience changes in their fear responses during sleep when they are not aware of the process, Hauner says. In that way, they wouldn't have to go through confronting the feared object or situation as much as they would in current therapy, she says.

"This is a new area of research," she adds. Further testing could look at whether the approach would produce long-term effects, she says. Also, the study examined memories created in a lab so further research could look at whether the approach would have an effect on pre-existing fear memories, she says.

"The study is important and exciting because it's a reminder that sleep doesn't just improve or consolidate memory," says Mark Mahowald, an American Academy of Neurology member who was not involved in the research. "It can extinguish memories."

"The extinction of memory during sleep could be important for people with PTSD and chemical dependencies," says Mahowald, a professor of neurology at the University of Minnesota Medical School in Minneapolis. "Further research could look at relapse prevention."

Read more here

Sniffing out the Brain's Predictive Power: Human Brain 'Smells' What It Expects Rather Than What It Sniffs

In the moments before you "stop and smell the roses," it's likely your brain is already preparing your sensory system for that familiar floral smell. New research from Northwestern Medicine offers strong evidence that the brain uses predictive coding to generate "predictive templates" of specific smells -- setting up a mental expectation of a scent before it hits your nostrils.

Predictive coding is important because it provides animals -- in this case, humans -- with a behavioral advantage, in that they can react more quickly and more accurately to stimuli in the surrounding environment.

The study, published in the Oct. 6 issue of the journal Neuron, was led by Christina Zelano, a postdoctoral fellow in the lab of Jay Gottfried, M.D., associate professor of neurology at Northwestern University Feinberg School of Medicine and attending physician at Northwestern Memorial Hospital.

The researchers used functional MRI techniques and cutting-edge, pattern-based analysis to identify the existence of predictive coding in the olfactory cortex of the brain, where the sense of smell is housed.

While it may not be obvious that predictive templates in the olfactory system give modern-day humans a behavioral advantage, Zelano said people often overlook the power of the sense of smell.

"If somebody hands you a bottle of milk and asks, 'Is this milk rotten?' there may not be any visual clues to help you accurately determine if the milk has spoiled, so you rely on your sense of smell," Zelano said. "Our study indicated that if your brain can successfully form a template of a rotten milk smell, then you would more accurately determine whether that milk is rotten and therefore you are less likely to get sick. These predictive templates can give us an important advantage."

Read more: http://www.sciencedaily.com/releases/2011/10/111007103308