How is REM latency calculated?

How is REM latency calculated?

• A. (First REM epoch − First epoch scored as sleep) / 2
• B. First REM epoch minus First epoch scored as sleep
• C. First REM − First sleep epoch
• D. First REM epoch − Lights out

Answer: (B)

REM latency is the time from when you first fall asleep to when REM sleep first appears. In scoring, sleep onset is defined as the first epoch that is sleep after lights out. To calculate the latency, take the time of the first REM epoch and subtract the time of the first sleep epoch (sleep onset). In practice, with 30-second epochs, count the number of epochs between sleep onset and the first REM epoch and multiply by 0.5 minutes. If REM starts in the same epoch as sleep onset, the latency is 0.

REM latency is the time from when you first fall asleep to when REM sleep first appears. In scoring, sleep onset is defined as the first epoch that is sleep after lights out. To calculate the latency, take the time of the first REM epoch and subtract the time of the first sleep epoch (sleep onset). In practice, with 30-second epochs, count the number of epochs between sleep onset and the first REM epoch and multiply by 0.5 minutes. If REM starts in the same epoch as sleep onset, the latency is 0.