AP PSYCHOLOGY

Detailed explanation-1: -“Hypnic jerks typically occur when there is a shift from Stage 1 of Non Rapid Eye Movement sleep to Stage 2, ” explains Dr Senthil Nathan, neurologist at Fortis Malar Hospital, Chennai. Your sleep cycle is divided into Non Rapid Eye Movement (NREM) and Rapid Eye Movement (REM).

Detailed explanation-2: -A hypnic jerk is an involuntary twitch of one or more muscles that occurs as a person falls asleep. It tends to occur in stages 1 or 2 of sleep and disappear in stage 3, which refers to rapid eye movement sleep.

Detailed explanation-3: -Stage 1 NREM sleep is the first sleep stage you enter when nodding off. This sleep stage is when heartbeat, eye movements, brain waves, and breathing activity begin to taper down. Motor movements also diminish, although you may experience muscle twitches called hypnic jerks.

Detailed explanation-4: -Stage 1. Stage 1, also called N1, is essentially when a person first falls asleep. This stage normally lasts just one to seven minutes. During N1 sleep, the body has not fully relaxed, though the body and brain activities start to slow with periods of brief movements.

Detailed explanation-5: -Stage 2: This period of light sleep features periods of muscle tone (muscles partially contracting) mixed with periods of muscle relaxation. Your eye movement stops, heart rate slows and body temperature decreases. Brain waves become slower.