univaiheissa
Univaiheissa is a Finnish term that translates to "in the stages of sleep" or "during sleep phases." It refers to the different periods of sleep that a person experiences during a typical night. These stages are characterized by distinct brain wave patterns, muscle activity, and eye movements. Sleep is broadly divided into two main types: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
NREM sleep is further divided into three stages. Stage N1 is the lightest stage of sleep, where
REM sleep is the stage where most dreaming occurs. During REM sleep, brain activity resembles that of
The cycle of these sleep stages repeats several times throughout the night, with NREM stages typically preceding