Can the process of learning happen during sleep? If yes, does it involve new information, or only what was previously learned during the day?
Can we actually learn new things during sleep? Several studies have suggested links between sleep, memory and learning. For instance, a research performed last year showed that students were better able to remember foreign words after hearing them while they were asleep. Another study suggests that sleep, smells and learning might be linked. According to neuroscientist Jordan Lewis, the evidence appears to point at sleep being a memory-booster and not a platform from where we can learn previously unknown things.
In a statement to The Guardian, Lewis explains his belief that sleep helps to reinforce knowledge learned during the day.
Deep sleep has often been associated with strengthening the memory acquired during wakefulness. According to these theories, memory is shifted from a short-term scale to a long-term one. On the other hand, new information cannot be absorbed during sleep.
“Slow-wave or deep sleep has been recognised for some time as critical for memory consolidation – the stabilisation of memory from short-term to long-term,” says Lewis. “During slow-wave sleep, which tends to happen during the first half of the night, the firing of our brain cells is highly synchronised. When we measure sleep using electrodes attached to the scalp, slow-wave sleep appears as slow, high-amplitude oscillations.”
Other scientists have analysed sleep in relation to memory from other perspectives. For instance, French researchers manipulated memories of mice during their sleep earlier this year; the mice were shown to have responded to the modified memories when they woke up. Could this be indicating that new information can be learned during sleep? Well, the mice had electrodes fitted to their heads as they slept, a procedure we do not expect to be feasible for laymen to learn new stuffs during their sleep.
“Our brains have developed a pretty clever mechanism for helping us learn new information,” concludes Lewis. “Be kind to your noggin and give yourself enough sleep to take advantage of it.”