Memory Improved With Optimum Sleep
A while back there was some research suggesting that scents smelled while sleeping could help with learning by boosting the brain's ability to hold onto new memories.
Now new research out of Northwestern University has found that sound may work in much the same way on the sleeping brain, adding to a growing body of evidence that memories are processed better with optimum sleep.
The latest study appears in the November 20, 2009 issue of Science and examines whether sound cues linked to newly learned information help the brain hang onto that data.
"We have known that the memory system is quite active during sleep and that the memory can be strengthened at this time," says John Rudoy, lead author of the study and a neuroscience Ph.
D.
student at Northwestern.
The participants in this study, 12 young adults who were asked to learn a new task and then take a nap, were better able to hold onto the newly learned memory when they were exposed to sound cues during their nap, though none of them remembered hearing any sounds.
The task involved being shown 50 images, each appearing one at a time in different places on a computer screen.
The images had a matching sound - a meow with the image of a cat, shattering glass when seeing a wine glass.
The task the subjects did was to put the images in their original spot when they were presented, along with the matching sound, a while later.
This part of the study ended when the subjects could do this memory task two times with all the images.
Within the hour after finishing the memory task, the subjects were asked to take a nap in a dark, quiet space.
Electrodes were put on their heads to monitor brain activity.
Only after verifying the subjects were in a deep phase of sleep did the researchers play half of the 50 sound cues heard during the learning part of the experiment.
They also added 25 new sounds to the mix.
When they woke up, the subjects were given the memory task to do again.
After nap scores were worse than the scores before napping.
The researchers believe this shows some loss of memory over time.
But the recall of the correct location of specific images, after being exposed to sound cues for those images during sleep, was far better, even though there was no memory of hearing any sounds.
"The research strongly suggests that we don't shut down our minds during deep sleep," continues researcher Rudoy, "Rather this is an important time for consolidating memories.
" So does this mean there's a way to help us super-charge our learning capacity? It's too soon to know for sure.
For now, researchers believe that existing memories can be made stronger during sleep, but that new learning doesn't take place.
According to Howard Eichenbaum, PhD, who directs the Center for Memory and Brain at Boston University, the brain replays memories while we sleep, and sounds may well trigger more specific memories.
He'd like to see future work compare the amount of memory retention associated with sounds during sleep as opposed to more traditional ways of learning...
like studying.
This way students and actors everywhere would know which is more effective, listening while you're sleeping or studying a bit more when you're awake.
Now new research out of Northwestern University has found that sound may work in much the same way on the sleeping brain, adding to a growing body of evidence that memories are processed better with optimum sleep.
The latest study appears in the November 20, 2009 issue of Science and examines whether sound cues linked to newly learned information help the brain hang onto that data.
"We have known that the memory system is quite active during sleep and that the memory can be strengthened at this time," says John Rudoy, lead author of the study and a neuroscience Ph.
D.
student at Northwestern.
The participants in this study, 12 young adults who were asked to learn a new task and then take a nap, were better able to hold onto the newly learned memory when they were exposed to sound cues during their nap, though none of them remembered hearing any sounds.
The task involved being shown 50 images, each appearing one at a time in different places on a computer screen.
The images had a matching sound - a meow with the image of a cat, shattering glass when seeing a wine glass.
The task the subjects did was to put the images in their original spot when they were presented, along with the matching sound, a while later.
This part of the study ended when the subjects could do this memory task two times with all the images.
Within the hour after finishing the memory task, the subjects were asked to take a nap in a dark, quiet space.
Electrodes were put on their heads to monitor brain activity.
Only after verifying the subjects were in a deep phase of sleep did the researchers play half of the 50 sound cues heard during the learning part of the experiment.
They also added 25 new sounds to the mix.
When they woke up, the subjects were given the memory task to do again.
After nap scores were worse than the scores before napping.
The researchers believe this shows some loss of memory over time.
But the recall of the correct location of specific images, after being exposed to sound cues for those images during sleep, was far better, even though there was no memory of hearing any sounds.
"The research strongly suggests that we don't shut down our minds during deep sleep," continues researcher Rudoy, "Rather this is an important time for consolidating memories.
" So does this mean there's a way to help us super-charge our learning capacity? It's too soon to know for sure.
For now, researchers believe that existing memories can be made stronger during sleep, but that new learning doesn't take place.
According to Howard Eichenbaum, PhD, who directs the Center for Memory and Brain at Boston University, the brain replays memories while we sleep, and sounds may well trigger more specific memories.
He'd like to see future work compare the amount of memory retention associated with sounds during sleep as opposed to more traditional ways of learning...
like studying.
This way students and actors everywhere would know which is more effective, listening while you're sleeping or studying a bit more when you're awake.
