You have probably heard of or witnessed a discussion between parents and teenagers in which the young ones were sent to bed by the grownups, although they said they weren't tired at all.

Unfortunately for the parents, the children weren't lying nor were they to blame for anything, everything being connected to the activity of the brain.

A study published in the journal Sleep suggests that the need for sleep builds-up slower at teenagers than at pre-teens.

A study of 13 boys and girls between 10 and 16 years of age shows that the build-up of sleep pressure, or sleep need, during an extended period of wakefulness is slower in adolescents than in pre-teens. The study participants remained awake for 36 consecutive hours in a sleep laboratory, where their sleep electroencephalograms (EEGs) were continuously recorded by polysomnography.

The slower build-up of sleep pressure in mature adolescents is seen in their levels of EEG slow-wave activity, which tend to be high when the need for sleep is greatest, according to background information in the article. The researchers indicate that their findings may help explain the tendency of teens to go to bed later at night and sleep later in the morning.

"We propose that the higher tolerance to prolonged waking may prepare children for adult lifestyles and for performing tasks under sleep deficits that are common in adults of modern societies," the authors conclude.