From chronic insomnia help audiobooks,podcasts and sleeping pills. If you download books all night, they will gradually penetrate dreams. And what is most funny, sometimes you can even recall part of what was heard in the morning. Scientists have long wondered whether you need to be conscious to remember. It seems that yes - after all, all our precious memories are formed during the hours of wakefulness, when consciousness is at work.
However, there are more and more studies onthe fact that when we slide into an unconscious state in a dream, we do not lose the ability to memorize new material. That is, turn on the playing of a dictionary of new words, and the unconscious brain will learn these words - without any work or awareness, even after waking up.
Learning in a dream is possible
A recent study published in CurrentlyBiology, suggests that the idea of learning in a dream has roots. Scientists conducted an experiment with a group of 41 people who speak German, and found that participants' brains can absorb vocabulary from a made-up language and bind these words to German meanings during sleep.
This, of course, is far from exploring completelyA new language, including syntax, in a sleeping state. But on awakening, the participants were asked if the designated fictional word would be more than a shoe box (yes, this is a strange test), and the participants answered correctly with a much higher chance - not knowing that they had previously encountered this word.
"During the study, we found that the sleeperthe brain can actually encode new information and store it for a long time. Moreover, the sleeping brain is capable of creating new associations, ”says study author Mark Zust of the University of Bern.
Sleep and memory
We often think of sleep as idle time. But it is not.
Recent studies have shown that sleep helps the brain to clear, wash out toxic molecules that can eventually lead to Alzheimer's disease.
More importantly, sleep also reorganizesmemories. At certain stages of sleep, the brain reproduces memories in an accelerated mode: the neurons responsible for storing memories are again activated as a network, in essence, teaching the brain memory. This loss helps us cram important lessons and life experiences into a more permanent repository in our brain. Meanwhile, tangential memories - those that do not deserve special attention in the first place - are erased in order to open more storage space.
Some of this night work can be caught bydirect measurement of neural activity in the brain of rodents. Plant the mouse in a new maze during the day, and the neural networks activated during memory coding will start working at night.
From these rodent studies, scientists foundthat the hippocampus, a seahorse-shaped area hidden deep inside the brain, is associated with the outer layer of the brain, the cortex, during sleep, through activity waves that can be measured using an EEG device.
Learning in a dream
In this study, scientists took 41German-speaking volunteers of both sexes. Instead of teaching them the usual language, the team composed pseudowords, each of which was associated with a specific meaning, to make sure that one of the participants had no contact with the new language.
Instead of saying the words when the volunteers were asleep, the scientists decided to aim for a certain period of sleep: the so-called “peaks” during deep sleep, usually not associated with dreams.
During deep sleep, neurons coordinate theiractivity for short periods of time before falling again into a period of inactivity - to fall on the chart. These two states cycle through every half second.
"We suggested that the peaks of slow waves contribute to the coding of sleep, because the peaks distinguish between periods of relative nervous excitation," the authors explain.
When the volunteers fell asleep, each of them had an EEG device for monitoring brain functions, and scientists began to play verbal associations through earphones.
For example, the fictional word "tofer" meant“Key” and “guga” - “elephant”. Each pair of words was reproduced four times, in accordance with the rhythm of the sleeping brain, so that the second word coincided with the peaks of the waves. In total, the sleeping brain heard about 36 different pairs of words in more than 146 repetitions.
"The moment when the second word was reproduced wasimportant, because at that moment it was possible to form an association between one word and another, and therefore neural plasticity should be optimal, ”the authors explain.
Upon the awakening of the volunteers, the scientists showed thempseudowords and asked to portray whether the designated object is smaller or larger than the shoebox - as a way to penetrate unconscious memories.
“Implicit memories are difficult to articulate explicitly. We had to gain access to unconscious, implicit knowledge through questions about the semantic aspects of these new words, ”says Cust.
15 participants also received a brain scan using fMRI at the time of the decision-making attempt.
It is noteworthy that when the second word in a pair of words coincided with the state of sleep in a deep sleep, the participants could correctly characterize the made-up word by 10% above the chance.
"If you imagine" biktum "and" bird "sleepingpeople, their brain can establish a new connection between the well-known concept of "bird" and the completely new and unknown word "biktum", says Cust. “This trail in a dream remains during wakefulness and may affect how you react to“ biktum ”, even if you think that you have never encountered this word before. This is an implicit, unconscious form of memory - as if you “can feel it in your gut”.
Studying the data, scientists found that getting into peak states while presenting properties correlates with better memory after waking up.
This explains a number of previous controversies in sleep studies. The authors explain as follows: “The timing of the presentation of words regarding the sleeper's EEG was crucial for the success of sleep coding.
Looking at the student, but the sleeping brain, scientists found that the hippocampus and the brain region, usually associated with language learning, were also active during sleep learning.
This strongly contradicts everything we know about the hippocampus training - we believe that it is active only in the waking state.
"These brain structures appear to bemediate the formation of memory regardless of the prevailing state of consciousness - the unconscious during deep sleep, the conscious during wakefulness, ”says Züst.
Those who have already thought about creating a device for“Learning in a dream,” it is worth understanding that the idea of introducing a completely new vocabulary during sleep remains highly controversial. After all, dictionaries are based on knowledge, not on intuition. Moreover, scientists still do not know whether active learning during sleep can interfere with the more visible role of sleep in consolidating daytime memories.
"The practical significance of the unconsciouscoding during sleep for later study after waking up will ultimately depend on whether the first sleep coding session improves this training, ”the scientists said.
Is it not surprising that people are capable of such complex information processing, actually being unconscious? Share your opinion in our chat in Telegram.