If you're stuck on an issue that requires "outside the box" solutions, allow yourself the luxury of a few nights of rest. That sleep is fundamental to reinforce learning and creativity is a known fact, but the role played by its various phases is still being discussed. Now a new research hypothesis, which will be declined in the next five years, proposes that REM sleep (a phase that is repeated several times during the night and is characterized by rapid eye movements) and non-REM (composed of alternating light sleep phases to periods of deep sleep) work together, and in a complementary way, to facilitate creative thinking .
How to weave the canvas. The theory of Penny Lewis, neuroscientist of the School of Psychology of the University of Cardiff (Scotland), is illustrated in the journal Trends in Cognitive Sciences. "Imagine you already have all the memories you need, but having to restructure them - create connections between thoughts that you didn't connect, integrate elements that you didn't integrate, " says Lewis.
Several studies indicate that these unexpected relationships between known elements may spring up more easily after a night of sleep: Lewis analyzed the scientific literature on the subject to elaborate a model on how the different stages of sleep contribute to the "miracle".Also read: What is the secret of creativity? A good night's sleep can make the information we can't remember when we're awake easier to access. | Wade Morgen, Flickr
Well labeled files. According to the model, non-REM sleep has the task of organizing information into useful categories; the REM one, to help us see beyond these categories, to create original connections . When we fall asleep we enter non-REM sleep, which includes a lighter phase extended for most of the night, plus a phase of deep numbness - slow-wave sleep - in which millions of neurons activate simultaneously: in this phase, we do more difficult to wake up, and if it happens, we feel particularly disturbed.
Past studies have proposed that at this stage the hippocampus (a fundamental brain structure for learning and memory) re-proposes the accumulated memories during the day, and when these present similarities with our previous knowledge, they leave traces in the neocortex (the outermost layer of the brain, more recently evolved, deputed to higher cognitive functions ).
In this phase, the hippocampus and neocortex work hand in hand: according to Lewis, the former manages to control the memories to be reproduced, preferring those that are thematically linked, or from the related context, which can be categorized with the same labels. The neocortex is therefore urged to follow these well-organized schemes.What does he say, who speaks in his sleep?
After order, chaos. In the REM phase (the phase most traditionally accompanied by dreams), on the contrary, the hippocampus and cortex do not seem to cooperate: both are in an extremely flexible state, in which new neural connections can be formed or in which those present can be strengthened or weakened. If in the preceding phase the neurons worked as in a "chorus", in this we see a real cacophony, in which, however, we can distinguish some unexpectedly pleasant chords.
The neocortex is free to propose memories in different combinations, regardless of similarity. It can happen that among concepts that apparently are not related to each other, such as "Solar System" and "electrons", there are unexpected similarities: genius ideas and solutions outside the box are born (like, to follow the example brought by Lewis, the atomic model proposed by Earnest Rutherford, inspired precisely by the structure of the Solar System).
According to some theories, dreams are nothing more than a conscious manifestation of these processes of categorization, association, revolution and transformation of memories. In essence, the brain "looks at itself", while manipulating mnemonic traces.
Some parts of the model are supported by experimental evidences, others less: the purpose of Lewis is to explain the fascinating hypothesis as much as possible, so that it can be tested with scientific studies.