Enhancement of some brainwave activity during sleep in rats improves their performance on memory tests. Improving these abilities in people could lead to new treatments for dementia and other memory disorders.
Memories are encoded in unique patterns of activity between neurons. Every time we learn or experience something new, a subset of neurons forms connections. These connections are strengthened during sleep, strengthening memories. This process is known as memory consolidation.
Source: www.newscientist.com