The University of York researchers also demonstrated that when a memory is retrieved - when we remember something - it is updated with new information present at the time of remembering. The brain appears not to 'overwrite' the old version of the memory, but instead generates and stores multiple (new and old) versions of the same experience.
Lead researcher Scott Cairney said the study demonstrated that sleep strengthens both old and new versions of an experience, helping us to use our memories adaptively.
"In this way, sleep is allowing us to use our memory in the most efficient way possible, enabling us to update our knowledge of the world and to adapt our memories for future experiences," he added.
Corresponding author Gareth Gaskell noted that the study reveals that sleep has a protective effect on memory and facilitates the adaptive updating of memories.
Gaskell added, "For the sleep group, we found that sleep strengthened both their memory of the original location as well as the new location. In this way, we were able to demonstrate that sleep benefits all the multiple representations of the same experience in our brain."
The researchers pointed out that although this process helps us by allowing our memories to adapt to changes in the world around us, it can also hinder us by incorporating incorrect information into our memory stores. Over time, our memory will draw on both accurate and inaccurate versions of the same experience, causing distortions in how we remember previous events.
The study is published in the journal Cortex. (ANI)