Recent studies tell us yes, it is possible to learn languages and more. There is proof that the sleeping brain can translate new information and store it for long term, even making new associations. Scientists have long known that sleep is important for memory, but thought it pertained only to the retention and organization of memories we get when awake.
What this new research tells us is that our brains are listening to the world, and learning about it, even when our conscious selves are not present.
The idea that we can learn in our sleep has fascinated the minds of artists and scientists alike. The concept that we can improve our productivity by learning in our sleep is very appealing. Science is moving ever closer to understanding what goes on in the brain when we sleep and how our restful state affects learning and memory formation.
When we are awake we learn new things, but when we are asleep we refine them, making it easier to retrieve them and apply them correctly when needed most. This is important for how we learn but also for how we might help retain healthy brain functions.