PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -During sleep, we experience two alternating types or states of sleep over an 8-hour time period: NREM sleep and REM sleep. The cycle repeats itself every 90 minutes. NREM or Non-Rapid Eye Movement includes 4 stages of sleep.

Detailed explanation-2: -Approximately 75% of sleep is spent in the NREM stages, with the majority spent in the N2 stage.[14] A typical night’s sleep consists of 4 to 5 sleep cycles, with the progression of sleep stages in the following order: N1, N2, N3, N2, REM.[15] A complete sleep cycle takes roughly 90 to 110 minutes.

Detailed explanation-3: -"Every night your brain moves through several sleep cycles. Each cycle starts with light sleep, then you enter deep sleep, then dream then back to light. Each of these cycles is around 90 minutes, ‘’ he explained.