(Photo: shutterstock) (Photo: shutterstock)

Israel to the rescue! This time, finding a cure to one the world’s worst habits – smoking.

Rotten fish and eggs to cure a smoking addiction? Israeli scientists at the Weizmann Institute of Science in Rehovot have developed a new and innovative method to wean smokers from their unhealthy habit.

New Weizmann Institute research has taken “sleep learning” to the next stage. The research, which appeared in the Journal of Neuroscience, suggests that certain kinds of conditioning applied during sleep could induce a patient to change his or her behavior.

In an attempt to influence smokers, researchers exposed them to combinations of odors, namely cigarettes together with that of rotten eggs or fish, as the subjects slept, and then asked them to record how many cigarettes they smoked during the following week. The study revealed a significant reduction in smoking following conditioning during sleep.

Weizmann Institute

Weizmann Institute. (Photo: wikipedia)

The smoker came to associate smoking with the repugnant odor of spoiled eggs and rotten fish.

Dr. Anat Arzi of the Weizmann Institute’s Neurobiology Department, under the leadership of Professor Noam Sobel, has previously shown that associative conditioning, in which the brain is trained to associate subconsciously one stimulus with another, could occur during sleep if odors were used as the unconditioned stimulus.

Though volunteers who participated in the experiment did not remember the odors they had smelled during their sleep, their sniffing gave them away: The next morning they reacted unconsciously to tones that had been paired with bad smells by taking short, shallow breaths. The use of smell, explains Arzi, is central, as bad odors do not wake us, as opposed to other sensory stimulants that do.

This study was performed on 66 volunteers who wanted to quit smoking but were not being treated for the problem. Cigarette smoking was chosen for the study because it is behavior that can monitored and its change can be quantified.

After filling out questionnaires about their smoking habits, those in the sleep group spent a night in the department’s special sleep lab, during which their sleep patterns were closely monitored. At certain stage, they were exposed to paired smells, cigarettes and a foul odor, one right after the other, repeatedly throughout the night. Although they did not remember smelling the odors the next morning, the subjects reported smoking less over the course of the next week.

In contrast, subjects who were exposed to the paired smells when awake did not smoke less afterward.

Sobel and Arzi suggest that this method of modification of habits through conditioning may be a promising direction for addiction research because the brain’s reward center, which is involved in addictive behavior as smoking, is closely interconnected with the regions that process smell. Some of these regions not only remain active when we sleep, but the information they absorb may even be enhanced during slumber

Relating to her research, Arzi said that her team has not yet invented a way to quit smoking while sleeping. That requires a different kind of study altogether, she said. “What we have shown is that conditioning can take place during sleep, and this conditioning can lead to real behavioral changes. Our sense of smell may be an entry way to our sleeping brain that may, in the future, help us to change addictive or harmful behavior.”