The greater incidence of delayed sleep phase may explain why night owls seek help more often than larks - there are simply more of them.

The resultant effect on sleep phase, if any, is governed by the PRC.

This study found that sleep improved memory retention of emotional text only during late sleep phase, which was primarily REM.

This mutation results in less REM sleep and more time spent in earlier sleep phases.

A bedside base unit awakens the sleeper during the last light sleep phase before the desired waking time.

(Shifting the sleep phase by 3 hours per day may not always be possible; shorter increments of 1-2 hours are needed in such cases.)

"You're ready for the sleep phase?"

This adaptation to earlier sleep/wake times is known as "advancing the sleep phase."

Healthy people can advance their sleep phase by about one hour each day.

Since 2005, many products have attempted to monitor the user's sleep cycles through different methods to wake them at their lightest sleep phase.