On average, humans spend roughly a third of their lives asleep. This might sound like quite a long time, but sleep has been shown to be vital for “normal” human functioning. Without enough sleep, things go downhill for most people pretty quickly.
As well as being vital for getting through the day, sleep is well known to play an important part in the process of memory making – sleep helps us take newly formed “fragile memories” and make them “robust”. Through sleep, our brains hit the “save” button, allowing us to transfer memories to a long-term storage system.
Research from the Sleep Language and Memory (SLAM) lab at the University of York has focused on the relationship between sleep and language learning. This research has shown that sleep plays a role in strengthening our memories for newly learned words – for both adults and children.
We found that people who get more deep sleep show bigger improvements in their memory for new words after sleep. And that going to sleep after learning new words also allows those words to be embedded into the brain’s mental dictionary – meaning these words begin to behave like words we already know.
As part of this research, children learned new words before and after a period of wakefulness or sleep. Greater improvements in vocabulary learning were seen after a period of sleep, compared with the equivalent time spent awake. So in essence, children who learned new words then went to sleep were able to better recall the words, compared to the children who learned the new words and just stayed awake.
And with this in mind, the SLAM lab is now working out the optimal delay between learning something new and going to sleep. This includes the use of bedtime stories for vocabulary learning in children.