Learning in your sleep.
Apparently we can learn simple responses while we are sleeping. Unfortunately we can’t pick up French from playing the audio recording overnight. From Ed Yong over at The Scientist:
Several groups have tested for advanced forms of learning during sleep, like picking up the links between pairs of words. All such experiments have failed. The only positive results came from studies showing that a very basic form of learning known as classical conditioning can occur in sleeping rats and infants, which begin to associate two stimuli—say, a tone and a puff of air—if they are presented together.
By contrast, Arzi’s experiments used a different technique called “trace conditioning,” where the tone and the smells are separated by more than a second. “This is considered a more advanced type of learning, and unlike classical conditioning, it depends on the hippocampus,” she said. “This is the type of learning associated with more complicated cognitive tasks, and therefore finding it in sleep is potentially important and novel.”
Arzi also took steps to ensure that her subjects were not inadvertently waking up. Throughout her study, a sleep technician monitored the volunteers’ brain activity and halted the experiment whenever they showed signs of rousing. All such trials were left out of the final analysis.
Arzi’s volunteers only learned a very simple response, and it is not clear if we can pick up more complex information while sleeping. “This does not imply that you can place your homework under the pillow and know it in the morning,” she said. “There will be clear limits on what we can learn in sleep, but I speculate that they will be beyond what we have demonstrated.”