We have all heard the superstitious urban legend that if you sleep with a textbook under your pillow, you may retain some information: as if the information will seep from textbook into your brain. This act stems from the desperate desire to learn while we sleep. What if it was actually possible?
In an unprecedented study that looks at the ways in which the subconscious human learns, a new Weizmann Institute study appearing today in the Journal Nature Neuroscience has found that you can never go wrong with classics-classical conditioning, that is.
Researchers discovered that people can learn new information while they sleep, and this can subconsciously modify their waking behavior.
Prof. Noam Sobel and research student Anat Arzi, together with Sobel’s group in the Institute’s Neurobiology Department in collaboration with researchers from Loewenstein Hospital and the Academic College of Tel Aviv put subjects asleep and monitored their sleep states, breathing and heart rate. After a night of exposing them to alternatively pleasant and unpleasant odors, followed by a tone, scientists removed the odors on the following night and found that when a tone associated with an unpleasant smell was played, participants’ breathing became short and shallow. Conversely when a tone that was paired with a good smell was played, the subjects inhaled deeply.
The next day, the now awake subjects again heard the tones alone again – with no accompanying odor. Although they had no conscious recollection of listening to them during the night, their breathing patterns told a different story. When exposed to tones that had been paired with pleasant odors, they sniffed deeply, while the second tones – those associated with bad smells – provoked short, shallow sniffs. Researchers noted that the learned response was more pronounced during the REM phase of sleep, but the transfer of the association from sleep to waking was evident only when learning took place during the non-REM phase.
Sobel and Arzi suspect that this is because “dream-amnesia” or those parts during sleep where we forget our dreams occurs at the REM-stage. Therefore, though we may be more sensitive to external stimuli at this stage, any conditioning may not stick upon waking. By contrast, non-REM sleep is the phase that is important for memory consolidation, (also the phase that changes your dreams depending on external stimuli such as a running television) so it might also play a role in this form of sleep-learning.
Now that researchers know it is possible to learn while asleep, Sobel and Arzi intend to find the limits of sleep learning, what information can be learned during sleep and what cannot.
While this information may prove useful when trying to get your roommates from eating your stuff in the fridge, our hope is that further studies on this will ultimately give us la earning advantage over peers.
