Sleep as a Psychological Construct

Consciousness

the level of awareness an individual has of their thoughts, feelings, perceptions and existence

Psychological construct

an agreed upon description and understanding of psychological phenomena that cannot be overtly measured or observed

Normal Waking Consciousness (NWC)

a state of consciousness in which an individual is awake and aware

Altered state of consciousness (ASC)

a state of consciousness that is distinctly different from normal waking consciousness in terms of quality of experience and levels of awareness

Naturally occurring altered state of consciousness

a type of altered state of consciousness that occurs without intervention (e.g. sleeping, daydreaming)

Induced altered state of consciousness

a type of altered state of consciousness that occurs due to a purposeful action or aid (e.g. meditation, hypnosis, influence of alcohol and/or drugs)

Consciousness continuum

a visual representation of the different states of consciousness that progress from lower levels of awareness to higher levels of awareness

Sleep

a regular and naturally occurring altered state of consciousness that involves a loss of awareness and disengagement with internal and external stimuli

characteristics of sleep

• a reduced ability to control behaviour

• a reduction in the control we have over thoughts, for example, we lack control over what we dream about

• less accurate understanding of the passage of time

• perceptual and cognitive distortions.

Sleep stages

REM, NREM-1, NREM-2, NREM-3

REM (rapid eye movement) sleep

a type of sleep characterised by rapid eye movement, high levels of brain activity, and low levels of physical activity

NREM (non-rapid eye movement) sleep

a type of sleep characterised by a lack of rapid eye movement and is subdivided into three different stages

Sleep episode

the full duration of time spent asleep

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

Typical hypnogram for an average adults sleep episode

(see slides/book)

Characteristics of REM sleep

• sleeper is considered to have a highly active brain and less active body

• sleeper is virtually paralysed, most muscle movement is not possible

• light stage of sleep, sleepers can be woken fairly easily

• vivid dreaming tends to occur

• amount of time in REM sleep increases as an episode progresses, largest amount occurs immediately before waking

Characteristics of NREM sleep

• considered to have a less active brain

• physical movement is possible, body considered more active

• amount of time in NREM sleep is highest during the first half of a sleep episode

• becomes shorter with each sleep cycle

• divided into three stages

Biological Rhythms

repeated biological processes that are regulated by internal mechanisms