A new way to cram for exams? Sounds played during deep stages of sleep may help us remember.
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SYDNEY: Listening to specific sounds during sleep may help you strengthen memories of information learned while awake, a study published in the U.S. journal Science has found.
The findings suggest that our mind continues to receive and interpret external signals outside of the rapid eye movement (REM) stage of sleep - when dreaming occurs - and during deeper stages of sleep, generally associated with low levels of brain activity.
If this is the case, individuals wanting to consolidate certain memories over others, such as students cramming for an exam or learning a foreign language, could find a whole new avenue open up to them.
Sleep processing
"This study tells us something about how memories are processed during sleep," said the study's lead author, John Rudoy, a neuroscientist at Northwestern University, in Chicago, USA.
"From previous scientific literature it seemed that memories could be strengthened by a period of sleep," he said. "This shows that the strengthening process is specific - certain memories can be strengthened in favour of others - and that it can be influenced by external stimuli."
For the study, 12 participants were shown 50 images of objects, such as a cat or a kettle, with corresponding sounds, such as a meow and a whistle. Each image had a unique location on a computer screen, which participants memorised before being taken into a dark room to nap.
Sound cues
Half of the sound cues were then played to the participants once they had reached the 'deep sleep' stage of their nap, as determined by electroencephalographic (EEG) recordings.
When tested post-nap, it was found that participants were able to place the sound-cued objects more accurately than those not played during their nap. However, in the control experiment, in which participants were played the additional sounds without any sleep, there was no marked improvement.
"This study is interesting because it relates back to the sorts of things people have thought about in the past, like helping kids by playing them their timetables at night," said John Rostas, neuroscientist from the University of Newcastle, in New South Wales, Australia. "It puts some scientific objectivity and solidarity behind something that has long been speculated about without much evidence."
Location-based learning
This is an interesting study, but they failed to answer a question in my mind: Does hearing all of the sound cues also effect the memory? For some reason the scientists only played half of the sound cues, which seems a bit strange to me.
Half of what?
You're quite right. I had to go back and read it again, as I had originally read it as " half of the participants had the sound cues played..".
Maybe it's an example of "understand what I mean, not what I've typed"
Cues
Only half of the cues were played so that the memory of the other images could be used as a comparison.
I.E. - For one person:
Correctly placed images (with cues): 32/50
Correctly placed images (sans cues): 20/50
That would show that the cues did improve the knowledge retention.
They can't give all the cues and then none (or vice-versa) as they would have to change the images otherwise the images may be remembered from before (having now seen them twice) which would lead to an increased knowledge of their placement.
Changing the placement of the images would only serve to confuse the subject, so that's not really a viable option either.
The design of the experiment is far from perfect but I think the results are definitely significant.
Sound Cues
Sound does play an important role strenthening memory & functions of the brain. Sound (sub-sonic) too has an impact which can cause resonance in the brain, which is evident in the EEG pattern.
Lol
No.