Consciousness is the level of awareness an individual has over their thoughts, feelings, perceptions, and existence.
Psychological construct
A psychological construct is an agreed upon description and understanding of psychological phenomena that cannot be overtly (directly) measured or observed.
Normal waking consciousness (NWC)
Normal waking consciousness (NWC) is a state of consciousness in which an individual is awake and aware.
Altered states of consciousness (ASC)
An altered state of consciousness (ASC) is a state of consciousness that is distinctly different from normal waking consciousness
Sleep
Sleep is a regular and naturally occurring altered state of consciousness that involves a loss of awareness and disengagement with internal and external stimuli.
Sleep episode
Sleep episode: the full duration of time spent asleep
Sleep cycle
Sleep cycle: an approximately 90-minute-period that repeats during a sleep episode in which an individual progresses through stages of REM
and NREM sleep
REM
REM (rapid eye movement) sleep is a type of sleep characterised by rapid eye movement, high levels of brain activity, and low levels of physical activity.
NREM
NREM (non-rapid eye movement) sleep is a type of sleep characterised
by a lack of rapid eye movement and is subdivided into three different stages