Sleeping away to knowledge

While learning a language is child’s play, it becomes challenging with age. This is because of the adults’ superior cognitive function. While superior cognitive function — mental processes that lead to the acquisition of knowledge and allow us to carry out our daily tasks — is good for virtually everything else, it poses a huge hindrance when it comes to learning a new language. Hence adults struggle and in the process end up trying too hard, which actually hinders their learning ability. But now a groundbreaking experiment established it was possible to learn new words and their semantic associations from scratch while in the depths of sleep. Sounds incredible, right? Well, scientists believe that the brain’s channels for learning are also open during sleep.

In the study, published in Current Biology, researchers wanted to know if people can make meaningful associations between foreign words and their translations while in slow-wave sleep, a stage when a person has little consciousness of their environment. So participants slept to the sound of an audio recording that presented pairs of pseudo-words representing a non-existent foreign language and their translations. The goal was to see if the words would leave some sort of trace in the person’s memory, even if it was at an unconscious level. When they woke up, participants were presented with the fake words again, but this time without their translations. Because they didn’t know a recording was playing while they slept, they were unaware that their brains had heard some of the words before. They were then asked to imagine the object the pseudo word denoted, and to guess whether it was smaller or larger than a shoebox — an approach that allowed researchers to tap into their unconscious memory. Researchers found participants were able to correctly classify foreign words at an accuracy rate that was 10 per cent higher than random chance, as long as they heard the word at precise times during slow wave sleep. 

The result suggests that the approach the researchers used causes the brain to form memory traces, or changes in the brain that help us store a memory.

The idea that we can learn in our sleep is not new. On the contrary, such a concept had intrigued artists and scientists alike. The very possibility of emerging more creative after sound sleep that would drastically improve our productivity by learning in our sleep is very appealing. But could such a scenario ever become a reality?

The latest study in Current Biology opens with a tantalising prospect: “Learning while asleep is a dream of mankind, but is often deemed impossible because sleep lacks the conscious awareness and neurochemical milieu thought to be necessary for learning.”

Delicate neurological connections forming the basis of memory have been shown to strengthen during deep sleep, and previous studies have shown words learned during consciousness can be consolidated by being repeated to a sleeping person. Next time someone says that sleeping time is unproductive, counter them with this research.