Sleep Study Involving Noises and Smells Finds You Can Learn New Information While You Sleep

Posted on September 2, 2012

A new Weizmann Institute study has found that it is possible to learn while you sleep. The study involved exposing sleep subjects to a noise followed by a smell.

Sleeping subjects were exposed to a tone followed by a pleasant or unpleasant odor. Then they heard a second tone followed by an opposite smelling odor. The noises were not loud enough to wake the subjects sleeping in a special sleep lab where their sleep state was being constantly monitored. The researchers found that sleeping people will breathe more deeply when exposed to a pleasant odor just like when they are awake. They will also reduce inhalation if an unpleasant odor is introduced while sleeping.

When the awake subjects were exposed to the same tones (without any odor) the following day they reacted as if they were about to experience an odor. They breathed more deeply if they expected a pleasant odor was about to follow the tone and reduced inhalation if they expected an unpleasant odor was about to come their way. The people had successfully been programmed to expect an odor following a certain tone during their sleep. The researchers say the tone and odor response was more pronounced if people had been in a REM sleep cycle during their sleep.

The research was conducted by Prof. Noam Sobel and research student Anat Arzi. Arzi wants to follow up on the research to see where the limits of sleep learning lie. She said in a statement, "Now that we know that some kind of sleep learning is possible, we want to find where the limits lie - what information can be learned during sleep and what information cannot."

The study appeared here in Nature Neuroscience on August 26.