A younger brain (left) has a stronger presence of slow brain waves. Slow brain waves begin to diminish as we grow older (right). Image: Bryce Mander/Univeristy of California, Berkeley

It’s not new information that as we age, sleep gets harder to come by. It’s also well known that our memory isn’t the sharpest as we climb higher in years. Now researchers think those two slumps could be linked.

In a new study, neuroscientists at the University of California, Berkeley gathered 33 healthy participants, 18 of whom were in their 20’s, the other 15 were in their sixties and seventies. Researchers presented the participants with different word pairs, then asked them to recall the words 10 minutes later. Then the participants were asked to go home, sleep overnight, then return and recall the word pairs the following day. While the participants were remembering the word pairs, the researchers scanned their brains.

Not surprisingly, the older folks had a harder time recalling the words the following day. But sleep became a factor when researchers looked at the brain scans: Older adults had less slow brain wave activity. Slow brain waves occur when we’re asleep, transferring recently acquired information from the hippocampus to other parts of the brain for storage and creating long-term memories.

Older adults also tended to share a diminished medial prefrontal cortex, which is thought to play a significant role with slow brain waves. Since our brains tend to lose mass over time, this was nothing surprising, though it does provide a link between poor sleep and struggling with your memory bank.