Sleep Cycle Timeline is Dream eXplorer’s feature that offers a visual preview of your sleep cycles in order to help you determine the best time for lucid dreaming attempts. Let’s have a quick look at “the science of sleep” (1, 2, 3).
With an adult who sleeps approximately 8 hours per night, 4 to 5 sleep cycles exchange during that time. Each of them lasts 90-110 minutes and is divided into two broad types – REM (Rapid Eye Movement) sleep and NREM (Non-Rapid Eye Movement) sleep. Each of these types consists of a specific set of physiological and neurological features:
NREM stage 1 – Drowsiness
Drowsiness is the beginning of the sleep cycle and represents a transition from wakefulness to sleep. Body begins to relax, brainwaves change from beta (>13 Hz, prevalent in wakefulness) to theta (4-8 Hz).
NREM stage 2 – Light sleep
Stage 2 brings deeper bodily relaxation, ceasing of muscular activities and gradual shutdown of our senses. Brainwaves still prevail in theta, though occasional fluctuations (sleep spindles) appear.
NREM stage 3 – Deep sleep
Formerly divided into stages 3 and 4, this stage is called slow-wave sleep or deep sleep. In this stage delta waves (0.5-4 Hz) prevail. Bodily functions slow to the lowest daily levels, eye movement and muscular activities cease completely.
REM sleep
REM phase is the most active phase of sleep which occurs for the first time approximately 90 minutes after we go to sleep. In the first cycle it can last only a couple of minutes, but it lengthens with each next cycle on the account of shortening of deep sleep and can last nearly an hour in the last sleep cycle. Most dreams occur in REM phase when our brain emits beta waves similar to waking state.
Hypnogram showing sleep cycles by stages (4)
Sleep Cycle Timeline displays results (one months’ period) in three colored lines:
Default (yellow/red) – Default setting – time of sleep, divided into 90-minute intervals;
Calculated (grey/blue) – Takes first and last sleep cycle you entered and divides the entire time period into 90-minute intervals.
Entered (grey/red) – Takes actual sleep cycle times from your dream journal and displays the actual duration of each sleep cycle.
Being familiar with sleep cycles and REM phases can be of great help to dreamers. My own observations for example show, that using dream enhancers or practicing dreaming techniques in the evening (after sleep onset) brings very little to no results at all while I get much better success rate (in terms of becoming aware within a dream or even entering a dream directly from wakefulness without losing consciousness in the process) after 5-6 hours of sleep. Interestingly, this is well known as the Wake-Back-To-Bed method (WBTB) among dreamers… 🙂
Until next time – happy dreaming! =)
(1) https://www.healthambition.com/why-is-sleep-so-important/
(2) http://en.wikipedia.org/wiki/Sleep
(3) http://www.sleepfoundation.org/article/how-sleep-works/what-happens-when-you-sleep
(4) http://www.slicedlime.se/2009/05/how-to-stop-being-tired-and-start-living-with-energy