Final answer:
REM and NREM refer to different stages of sleep which involve distinct patterns of brain waves and are integral to cognitive functions like learning and memory. REM sleep includes rapid eye movement and dreaming, while NREM sleep is a deeper, more restorative sleep.
Step-by-step explanation:
REM (Rapid Eye Movement) and NREM (Non-Rapid Eye Movement) pertain to D. sleep. During the sleep cycle, a person alternates between NREM and REM sleep. NREM sleep consists of three stages, with each stage progressively deepening.
Stage 2 of NREM sleep is characterized by sleep spindles and K-complexes, which are specific patterns of brain waves. REM sleep is associated with dreaming and is characterized by rapid eye movement, increased brain activity that resembles wakefulness, and muscle paralysis (except for those that make respiration and circulation possible).
Both NREM and REM sleep are important for cognitive functions such as learning and memory. For example, sleep spindles during stage 2 NREM sleep have been implicated in memory consolidation.
The reticular formation plays a key role in transitioning between sleep and wakefulness, and monitoring its activity could provide insights into these processes. Issues with these sleep stages can lead to sleep deficits, which may have psychological and physiological consequences.