If you are rewarded during learning, it helps your brain to retain new information, and daytime naps amplify this feature. Lead author Kinga Igloi, a postdoctoral researcher from the Department of Neuroscience, stated that during sleep the brain has the power to be selective and cement knowledge with rewarding values. It develops an adaptive approach to gather information to preserve and use it in times of need.
The aforementioned study comprised of 31 healthy volunteers who were divided into sleep and wake groups, in a random fashion. Participants from each group had to look at and memorize 8 pairs of images, and were informed that 4 of which would garner a bigger reward if remembered correctly. A 90-minute break followed, where the sleep group had a daytime nap, while the wake group just rested. The group was tested immediately about their memory of images, and asked to record their confidence levels on giving the right answer. The same process was repeated 3 months later.