One of the explanations the science has come up with for the healing power of sleep is that sleep may contribute to neurogenesis, the formation of new nerve cells in the brain. Without sufficient sleep, neurons may not have time to repair all the damage, and so could malfunction during the day.
Sleep is necessary for the brain to process and consolidate knowledge and for memories to form. Neuroscientists say that during sleep the hippocampus (where memory is stored) becomes highly active and moves knowledge from short-term memory to long-term memory.
The memories laid down by the sleeping brain are of two kinds. Declarative memory is memory for information – facts, dates and names. Procedural memory is what allows us to do things like playing a musical instrument or riding a bicycle. Scientists think these two types of memory are influenced by different parts of the sleep cycle and they are really necessary to have a good memory.
According to animal studies, when you perform a task, the brain cells fire in a certain sequence. If you then fall asleep, the same cells automatically fire in an identical sequence without being distracted or disrupted by incoming visual stimuli.
There is a consistent pattern: Learn something new during the day, consolidate what you have learned during a good night’s sleep, then remember or perform the task better in the morning. This is the ultimate benefit of sleep.
Even a nap in the middle of the day may benefit some learning, according to a recent study. Sleep appears to enhance the declarative memories and make them easier to recall.
Now you have one more tip to learn languages: Sleeping!