“Just like a nostalgic grandparent flipping through old photo albums, our brains constantly replay memories from past events in our lives as we sleep.
It may seem overly sentimental at first, but our minds aren’t just looking to reminisce and remember the good times. All of that brain activity while dreaming serves to strengthen and preserve existing memories, all while simultaneously finding some room for any new memories we may have made over the previous day.
Those are the main findings from a fascinating new study just released by the University of California, San Diegothat investigated neural activity during sleep. The research team at UCSD says that no memory is set in stone within our minds; any memory can be lost, and sleep is when our minds rejuvenate old memories via replay and refine/make room for new memories.
Imagine your memory is a warehouse. Each night as you fall asleep the night crew begins its shift and takes stock of the warehouse’s inventory and any available space for new deliveries.
‘The brain is very busy when we sleep, repeating what we have learned during the day. Sleep helps reorganize memories and presents them in the most efficient way. Our findings suggest that memories are dynamic, not static. In other words, memories, even old memories, are not final. Sleep constantly updates them,’ explains lead study author Maksim Bazhenov, Ph.D., professor of medicine at UC San Diego, in a release. ‘We predict that during the sleep cycle, both old and new memories are spontaneously replayed, which prevents forgetting and increases recall performance.'”