Rehearsing Memories During Sleep Helps You Remember More
April 13, 2013

Rehearsing Memories During Sleep Helps You Remember More

April Flowers for — Your Universe Online

A group of researchers at Northwestern University wondered, “why do some memories last a lifetime while others disappear quickly?”

The new study, published in a recent issue of the Journal of Neuroscience, suggests memories rehearsed, during sleeping or waking, can have an impact on memory consolidation and improve what is remembered later.

When a memory has a high value -- for example, associated with making more money -- the memory is more likely to be rehearsed and consolidated during sleep. This insures that it will be remembered later. The researchers, through the use of a direct manipulation of sleep, revealed a way to encourage reactivation of low-value memories.

Participants were asked to remember the location of objects on a computer screen during the experiment designed by Delphine Oudiette, a postdoctoral fellow in the department of psychology at Northwestern. Each object had a different value assigned, informing the participants how much money they could make if they remembered it later on the test.

"The pay-off was much higher for some of the objects than for others," explained Ken Paller, professor of psychology at Northwestern. "In other words, we manipulated the value of the memories -- some were valuable memories and others not so much, just as the things we experience each day vary in the extent to which we'd like to be able to remember them later."

Each object was accompanied by a characteristic sound as it was shown on the screen — for example, a whistling sound would accompany a tea kettle. Some of the sounds were played alone, softly, during both states of wakefulness and sleeping to remind participants of low-value items. The research team found the participants remembered low-value associations better when the sounds were presented during sleep.



A large number of memories that are stored during the day are not remembered.


The selectivity of memory consolidation is not well understood, according to Paller. The majority of prior research into memory has focused on what happens when you first form a memory and when you retrieve a memory.

