Chapter 6: The demand for sleep

• 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 overly measured or observed.
• Normal Waking Consciousness (NWC)

  State of consciousness wherein an individual is awake and aware.
• Altered State of Consciousness (ASC)


  State of consciousness that is different from normal waking consciousness in terms of quality of experience and levels of awareness.
• Naturally Occurring ASC


  Altered state of consciousness that occurs without intervention.
• Induced ASC


  Type of ASC that occurs due to a purposeful act or action.
• Consciousness Continuum 


  A visual representation of the different states of consciousness that progresses from lower levels of awareness to higher levels of awareness.
• Sleep 


  A regular and naturally occurring ASC the involves a loss of awareness and disengagement with internal and external stimuli.
• REM (Rapid-Eye Movement)


  A types of sleep characterised by rapid eye movement, high levels of brain activity and low levels of physical activity.
• NREM (non-Rapid Eye Movement)

  A type of sleep characterised by a lack of rapid eye movement an dis subdivided into 3 stages.
• Sleep Episode 


  The full duration of the 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.
• Electroencephalograph (EEG)


  Device that detects, amplifies and record the electrical activity of the brain.
• Electromyograph (EMG) 


  Device that detects, amplifies and records the electrical activity of body muscles.
• Electro-oculograph (EOG)


  Device that amplifies, detects the electrical activity of the muscles around the eyes.
• Sleep Diaries 


  Record containing self-reported descriptions from an individual about their sleeping periods, including an estimated time spent sleeping and judgements they might have about the quality and nature of their sleep.
• Video Monitoring


  Use of cameras and audio technologies to record an individual as they sleep.
• Biological Rhythms 


  Repeated biological processes that are regulation by internal mechanisms.
• Cicardian Rhythms 


  Biological and behavioural changes that occur as apart of a cycle that lasts around 24 hours.
• Sleep-Wake Cycle


  24-hour-cycle that is made up of time spent sleeping and time spnt awake and alert.
• Ultradian Rhythms 


  Biological and behavioural changes that occur in a cycle that lasts less than 24 hours.
• Suprachiasmatic Nucleus (SCN)


  Area of the hypothalamus that is responsible for regulation an individuals sleep-wake patterns.
• Pineal Gland 


  Gland in the brain responsible for the production and release of melation.
• Melatonin


  A hormone released by the pineal gland typically at night-time to induce sleep as part of the sleep-wake cycle.
• Cortisol


  A hormone that is responsible for the increasing alertness and maintaining heightened arousal.