If you have found yourself forgetting things during the day, it might not be a sign of old age but instead the result of your brain having a mini-snooze, new research suggests. According to a study conducted by the University of Winconsin-Madison in the US, moments of absent-mindedness can be the result of nerve cells in the brain temporarily going into a dormant state - or having a nap. In the past scientists believed that not getting enough shuteye affected the whole brain resulting in instances such as micro-sleeps during the day, during driving for example. However, this new research indicates that parts of the brain are impaired even before we reach this stage. This study which sheds new light on the way our brain operates examined the behaviour of rats who had been deprived of sleep for long periods. Monitoring the brain activity of the rats revealed areas of local sleep, even when the animals were awake.