Nap time essential for babies' language development
Photo by Carlo Navarro on Unsplash
Every parent looks forward to nap time especially when they have a young baby.
But while nap time allows parents a brief moment to breathe, relax and possibly get in some much-needed shut eye, they are also quite beneficial to the babies themselves.
A new study from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, shows that naps help the brain to develop and process information picked up during the day.
The researchers were examining how babies between six and eight months old learn to realise that words are not just noise, but actually refer to objects and ideas. In order to keep the babies’ existing knowledge from tainting the experiment, they used imaginary toy-like objects—which they called “Zusers” and “Bofels”—to assess the value of a midday nap.
They found that non-nappers couldn’t tell if a newly introduced object should be called a Zuser or a Bofel. After a 30-minute nap, however, the adorable test subjects could distinguish between the right and wrong terms. And after 50 minutes, the researchers saw a brain pattern that until now has only been seen in older children and adults. Called the N400 component, it is a sign that the babies had formed a solid mental bond between word and object.
"Our results demonstrate that children hold real word meanings in their long-term memory much earlier than assumed. Although the brain structures relevant for this type of memory are not fully matured, they can already be used to a distinguishable extent", explains Angela D. Friederici, director at MPI CBS and senior author of the underlying study which has recently been published in Current Biology.
In this context, one stage of sleep could be of particular importance: The duration of the second of the four stages of sleep, in particular, seems to have an important influence on the development of lexical memory. "During this light sleep, the transition from a simple early developing form of lexical memory to an advanced later developing form evidently takes place", says study leader Manuela Friedrich. "These two types of memory which develop during sleep are comparable with those that we know from infant development. Whereas during sleep there are just minutes in between the two types, in typical development there are months." The formation of memory content in sleep clearly takes place in fast motion.
"In our study, however, the babies received such a lot of information which they normally pick up within a longer time period", Manuela Friedrich adds. "But only during sleep, when the child's brain is disconnected from the outer world, can it filter and save essential relations. Only during the interaction between awake exploration and ordering processes while sleeping can early cognitive and linguistic capabilities develop properly."