How does sleep affect memory? We spend a significant part of our lives sleeping. Of course, it is a pity to lose so much time, but without proper sleep, it is impossible to spend time in an active way. If in youth we can still afford sleepless nights before preparing for exams, then with age, the effect of sleep on our well-being becomes more and more tangible.
Let’s take a look at two species of memory.
Motor memory
It involves the memorization, preservation, and reproduction of various movements. It lies at the basis of all household and labour skills, as well as the skills of walking, hammering a nail, and writing. Without movement memory, we would have to learn everything all over again. Motor memory provides coordination and the sequence of movements.
By the way, our speech is also based on motor memory. And each of us knows from ourselves or has seen from others how difficult it is to speak a language, especially when learning a foreign language.
Learning a new foreign language is always a complex and long process. Despite the fact that it is very valuable to know the languages of other countries and peoples, it does not become easier to learn them. As we noted earlier, there is a connection between sleep and foreign language acquisition.
For example, it is better to learn new words before sleeping and then go to bed, rather than to spend the whole night trying to learn new words from a foreign language. Thus, the result in the morning will be much more effective with the first approach.
However, learning a new language while sleeping is impossible. Especially such a complex one as, for example, Chinese. Small students are unlikely to cope with this task without a children’s tutor for learning Chinese. The process will be much faster and more efficient when they interact with the teacher. In addition, the tutor will always tell where there are gaps in knowledge and select the appropriate method for each individual student.
It is necessary to find out exactly how the human brain works during sleep and how to memorise foreign words. In one study in which participants were shown unfamiliar words after they had heard them in their dreams, the language area of the subjects’ brains was activated. It is directly related to the memorization of new words and is also one of the main centres of memory. It can be concluded that the brain centres, on which learning depends, work even when a person is sleeping.
This method of teaching has a place, but at this stage of research, scientists have not yet understood how to use it correctly for the benefit of education, because:
- a person can only memorise facts, and not learn words, this is not enough to fully master a new language;
- such learning in a dream will not be able to provide the student with information about the grammar of the language, because a clear mind is needed to understand and remember it;
- the pronunciation of words is not trained, respectively, the student will not be able to say what he remembers;
- during such language learning in a dream, grammar is not taken into account, because the student only listens to the necessary audio materials.
Declarative memory
It is responsible for our thought process and the processing of data entering the brain. Declarative memory is the ability to give a clear, coherent account of past individual experiences, a sense of familiarity with those experiences. A sleepy person may not remember all the information that he is able to reproduce in a rested state.
Scientists have found a curious fact: people who sleep little are much worse at remembering good news, they focus on negative emotions. We can say that a lack of proper rest can lead to depression and neurosis.
For short-term memory to turn into long-term memory, new interneuronal contacts must form in the brain, and the formation of such contacts best occurs during the sleep activity of nerve cells.
The transformation of short-term memory into long-term memory is called memory consolidation, and neuroscientists are hard at work trying to figure out how and why this happens. Quite a long time ago, we managed to find out that the consolidation of memory goes very well during sleep. That is, in order to remember the textbook read before the exam, you need to sleep, and then the information, as they say, settles in the head, that is, goes into long-term storage. There is plenty of evidence for a link between sleep and memory.
Lack of sleep leads to serious disruptions in the production of protein in the hippocampus, the part of the brain’s limbic system responsible for memory. In turn, this leads to disturbances in the formation of memories.
If a person does not get enough sleep, then there is a violation of neurogenesis. That is the ability of cells to restore, and build new connections to ensure basic functions. In this regard, in cases of lack of sleep, learning ability worsens, it is more difficult for a person to assimilate new information, his thinking processes are disturbed, and there are difficulties with systematisation. Premature ageing of the brain begins to occur, that is, the process of slowing down the rate of formation of new connections and new cells. With ageing, the brain slows down neurology, the processes that ensure the development of new cells, and their normal functioning, so that there are no inflammatory processes in the brain, and regeneration proceeds correctly.
Sleep is a kind of cleansing for the brain and psyche, because, during sleep, detoxification from decay products occurs.
In conclusion, sleep doesn’t just help keep memories longer, it transforms them. During sleep, the connections between neurons are not only strengthened but also rebuilt. This also explains why adequate sleep has a positive effect on creative thinking.
