How Sleep Supports Your Child’s Brain and Memory Growth

Scientists have recently uncovered how sleep helps form memories—and the findings are fascinating! While it's long been known that sleep plays a vital role in moving memories from short-term to long-term storage and supporting nerve growth, researchers have now pinpointed the exact mechanism behind this process.

Medical professionals have also long observed that poor sleep can delay the development of essential skills like crawling, rolling, walking, and talking. Now, science gives us a clearer understanding of why that happens.

In earlier studies, scientists observed that teaching mice a new motor skill (like balancing on a rotating rod) led to the formation of new dendritic spines in the brain. These tiny structures connect neurons and allow information to travel between brain cells across synapses. More dendritic spines mean more synaptic connections—essentially, more "brain power" for learning.

A new study from the New York University School of Medicine revealed that sleep not only increases the number of these spines but also protects them from being pruned away—even when the brain is learning multiple tasks. In contrast, when the mice were sleep-deprived, fewer spines formed, and those that did were quickly lost. Without sleep, the brain couldn’t consolidate new skills or move memories from short-term to long-term storage.

Why? Because during non-REM (deep) sleep, the brain replays newly learned skills, reactivating the same neurons involved in the learning process. This repetition strengthens synaptic connections and stimulates the growth of new spines, essentially reinforcing and preserving what was learned.

So what does this mean for you and your child?

Quite simply—sleep matters more than we even realized. This is yet another incredible example of how essential sleep is, not just for rest, but for growth, development, and learning.

If your baby struggles with short naps (less than 45 minutes) or frequent night wakings past 4 months of age, chances are they aren’t getting enough deep non-REM sleep—the exact phase where all this amazing brain development happens.

As science continues to unlock the mysteries of sleep, we remain in awe.