In a world where the border between work and free time is increasingly blurred, the time when we sleep and dream may be the last area completely free of work. We are (often voluntarily) trying to change that. Many try to sleep less (to different and sometimes extreme degrees, like those experimenting with polyphasic sleep) in order to work more, often motivated by the productivity mindset. A correlation has been observed between lack of sleep or disruption of sleeping patterns and the onset of dementia.