From sleep onset to the first epoch of REM is referred to as what?

The correct term for the period from sleep onset to the first epoch of REM sleep is REM latency. This measurement specifically indicates the time taken for an individual to enter REM sleep after falling asleep, which is a crucial aspect of sleep studies and contributes to understanding sleep patterns and potential disorders.

When evaluating this measurement, it helps clinicians assess the stability of sleep architecture and can provide insights into various sleep disorders. In contrast, sleep latency refers to the total time taken to fall asleep from the time of going to bed, while mean REM latency is a statistical average of REM latency across multiple sleep cycles. Mean sleep latency refers to the average time it takes for a person to fall asleep during multiple nap opportunities. These terms serve specific roles in the context of sleep studies, but none directly refer to the time interval being asked in the question.