Sleep means much more than only relaxation for our brain. The flow of detail from the sensory organs is largely cut off while we sleep, but many regions of the brain are especially working. Most brain expert’s today trust that the sleeping brain retrieves new experiences, thereby consolidating fresh knowledge and integrating it into the existing memory by growth, dismantling or re-linking neuronal connections. This means that sleep is vital for memory.
The Max Planck experts have found this to be the case even in toddlers and infants. In order to study the effect of sleep on infant memory, they invited parents to participate a study with their 9 to 16 month old kids. During the trial session, the infants were frequently shown pictures of certain objects while hearing the untrue names assigned to the objects. Some things were similar to each other, varying only in their proportions, shapes or in certain details. The similar items, which belonged to the same category according to their colors, were always given the same titles. During the process, the experts recorded the infant’s brain activity using EEG (electroencephalography).
Our groups of infants spent the next 1 to 2 hours sleeping in their prams while an EEG (electroencephalogram) was recorded, while the other stayed awake, going for a walk in their prams or enjoying in the examination room. In the subsequent experiment session, the experts again presented the infants with image- word pairs – this time both in the same mixtures as the learning sessions and in fresh mixtures – and again measured their brain action while doing so.
The analysis of brain activity presented that the infants had learned the titles of the individual objects during the trail session, irrespective of their age. The condition with categorization, anyway, was different. At the close of the training sessions, they were not capable to assign fresh objects to the names of similar things which they had heard several times.
During the subsequent exercise session, the brain activity of the infants who had slept after the exercise session was amazingly different from that of the group who had remained awake. While the group who had remained awake had forgotten the titles of the individual objects, the kids in the sleep ground memorized the object-word mappings. There were also major differences in their capabilities to categorize the objects. The infants who slept after the exercise session linked new objects to the titles of similar looking objects,” Manuela Friedrich of the Max Planck Brain sciences and Human cognitive institute says.