You can learn a new language when you sleep deeply

Researchers at the University of Bern discovered that it was possible to learn new vocabulary in a foreign language during the deep sleep phases of a district – and to unconsciously find it at home. awakening.

People have long wondered if "unproductive" sleep time could be used to learn, for example, a new language. But to date, sleep research has focused on consolidating the memories that have formed when you are awake, rather than on learning to sleep.

However, we know that sleep facilitates the process of learning in that the information learned during the day is reproduced in the sleeping brain. This reinforces still fragile memory traces and integrates new information into the learner's existing stock of knowledge.

Katharina Henke, Marc Züst and Simon Ruch of the Institute of Psychology and the Interfaculty Research Cooperation "Decoding Sleep"external link at the University of Bern wanted to know if it would be the same for new information arriving while someone sleeps.

"These investigators have now shown for the first time that new foreign words and their translation words could be badociated during a midday nap to badociations stored in the waking state," said a statement from the University of Bern.external link I said.

The results were published in the scientific journal Current Biology.external link

'Up-States'

The researchers submitted a test to 41 sleepy participants to see if their brain was acquiring the vocabulary of an invented language during their so-called "positive states" when the brain cells are active. In deep sleep, brain cells are usually active for a short time before becoming briefly inactive (during a slowdown). The two states alternate every half second or so.

The researchers found that semantic badociations between words of an artificial language played during sleep and their translations into German were only coded and stored if the second word of the pair was repeated over and over during reading.

For example, if a sleeping person had heard the pair words "tofer = key" and "guga = elephant", she would be better able to determine if the foreign words read by sleep are called something big ("guga") or small ("tofer"). After awakening, the total success rate was 60%.

"It was interesting to note that the linguistic areas of the brain and the hippocampus – the essential memory of the brain – have been activated when recovering the vocabulary learned through sleep, as these brain structures normally facilitate the learning of a new vocabulary upon waking, "said Züst, co-first author of the article .

"These brain structures seem to mediate the formation of memory regardless of the dominant state of consciousness – unconscious during deep sleep, conscious during waking ".

Theory of sleep

In addition to possible practical uses, this new evidence in sleep learning is challenging current theories of sleep and memory, the University of Bern said. The notion of sleep as an encapsulated mental state into which we are detached from the physical environment is no longer tenable, he added.

"To what extent and with what consequences deep sleep can be used for the acquisition of new information will be the subject of research in the coming years," commented the head of the research group, Henke .

In particular, it remains to be determined whether the acquisition of relational vocabulary during sleep would stimulate further learning of the same vocabulary upon waking, noted the researchers in the study.