Sleep On It, Your Memory Will Improve
“I’ll sleep on it” is a phrase people say when they are going to think about something, but what if sleep actually helps you remember new information and improves your memory? Researchers at the University of York and Harvard Medical School suggest that sleep may have such an effect on memory.
Sleep helps people remember new words and enhances memory
Results of the new study are important because it is the first time scientists have been able to observe how sleep has a role in reorganizing new memories and to understand a critical factor in the transfer of information in the process. Researchers utilized two groups of volunteers in their study.
Volunteers in one group were taught new words in the morning and tested on their memory of the words after learning them and then again in the evening, with no sleep in between. These individuals did not improve in their memory of the words during the re-test in the evening.
Volunteers in a second group were taught new words in the evening, after which they immediately took a test. These individuals then slept overnight in a lab and had their brain activity monitored using an electroencephalogram (EEG).
When the volunteers in the second group were retested in the morning after a night of sleep, they were able to remember more words than they had recalled immediately after learning them the night before. They also were able to recognize the words faster, which suggests sleep strengthens new memories.
When researchers evaluated the volunteers’ brainwaves, they found that deep sleep rather than rapid eye movement sleep or light sleep strengthened new memories. Further evaluation showed that volunteers who had more sleep spindles during sleep were better at integrating the new words with existing knowledge.
Sleep spindles are brief and intense bursts of brain activity that indicate information is being transferred between different memory areas in the brain; specifically, the hippocampus and the neocortex. The hippocampus stores memories separately from other memories, while the neocortex contains memories that are linked with other knowledge.
Results of this study suggest that if you “sleep on it,” you could improve your memory. Dr. Jakke Tamminen, the study’s lead author, points out that “New memories are only really useful if you can connect them to information you already know.” He and his team found the “brain activity during sleep that organizes new memories and makes those vital connections with existing knowledge.”
University of York