School work, after school sports and various other activities that crowd the daily lives of teens may cause their sleep time to suffer. It is thought that while we sleep, toxins that have built up in our brains are cleared out and brain connections are improved. In turn that enhances memory, learning and problem-solving skills. None of the teens in the study got the recommended eight to ten hours sleep each night, but of the three different sleep groups, those who got the most sleep enjoyed better brain function, such as how well they did during tasks. Authors of the study in the journal Cell Reports say given the importance of sleep, we need to learn why some children go to bed later and sleep less than others. Is it because they are playing video games or on their smartphones.