chapter 6

• Psychological construct

  An agreed upon description and understanding of psychological phenomena that cannot be directly measured or observed.
• Consciousness

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

  
  

  -A psychological construct

  
  

  -reflected by a continuum from lower levels of awareness to higher levels of awareness.
• States of consciousness

  • Normal waking consciousness
  • Altered state of consciousness
• Normal waking consciousness

  A state of consciousness in which an individual is awake and aware, e.g. focused attention, relaxed state.
• Altered state of consciousness

  A state of consciousness that is distinctly different from normal waking consciousness in terms of quality of experience and levels of awareness, e.g. sleep, meditation, drowsiness, daydreaming, coma, alcohol-induced.
• Sleep

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

  
  

  A psychological construct

  naturally occuring means it occurs without intervention or purposeful action.

  
  

  Characteristics include

  - reduced ability to control behaviour

  -reduction in the control we have over thoughts

  -less accurate understanding of the passage of time.
• Types of sleep

  • REM (rapid eye movement) sleep
  • NREM (non-rapid eye movement) sleep
• REM sleep

  A type of sleep characterised by rapid eye movement, high levels of brain activity and low levels of physical activity. Makes up approx. 20-25% of a sleep episode. Amount of time spent in REM sleep increases as the sleep episode progresses.
• NREM sleep

  A type of sleep characterised by a lack of rapid eye movement and is subdivided into three stages (NREM1, NREM2 and NREM3). Makes up approx. 75-80% of a sleep episode. Amount of time spent in NREM sleep is highest during the first half of a sleep episode.
• Sleep episode

  The full duration of time spent asleep, made up of multiple repeated 90-minute sleep cycles of REM and NREM sleep. Visualised in a hypnogram to track the proportion of time spent in each stage of sleep, including awakenings.
• REM sleep

  • High brain activity, body is virtually paralysed with no muscle movement (except rapid eye movement), vivid dreaming tends to occur, sleeper is easily woken.
• NREM1 sleep

  • First stage of sleep, lightest stage of sleep (sleeper loses awareness but is still aware of some stimuli in the environment so is easily awoken), hypnic jerks (sudden muscle contractions) may occur, feelings of floating or falling within a hypnagogic state may occur.
• NREM2 sleep

  • Relatively light sleep but sometimes described as moderate sleep, continued slowing of heart rate, breathing, muscle activity and body movements, requires more intense stimuli to awaken (compared to NREM1).
• NREM3 sleep

  • Deep sleep, difficult to wake the sleeper (if woken, likely to feel drowsy/disoriented and experience sleep inertia), sleepwalking and sleep talking are most likely to occur.
• EEGs, EOGs and EMGs collect quantitative data. They are objective measures.
• Sleep diaries

  A 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. They are a subjective measure.
• Video monitoring

  The use of camera and audio technologies to record an individual as they sleep. The interpretation of video monitoring is subjective. It is often used in conjunction with physiological measures like an EEG, EOG and EMG to give validity to a phenomenon.
• A researcher was interested in the effect of sleep deprivation on people's cognitive processing. For one week, participants were asked to spend each night in a sleep laboratory and were allocated to one of two groups: one where participants were exposed to large amounts of bright light in the evening (causing them to be deprived of sleep) or being encouraged to recreate their usual night-time routine in the sleep lab. During the day, participants went about their day as normal.
• Data collection methods used by the researcher

  1. Exposing participants to large amounts of bright light in the evening (causing them to be deprived of sleep)

  2. Encouraging participants to recreate their usual night-time routine in the sleep lab

  3. Participants going about their day as normal during the day
• Suggest data collection methods that would be used by the researcher. Justify why these measures would be used and discuss any potential limitations.
• Unit 4 aos 1 – How DOES SLEEP AFFECT MENTAL PROCESSES AND BEHAVIOUR?
• Describe how physiological responses associated with sleep are measured through electroencephalography (EEG), electromyography (EMG) and electro-oculography (EOG), with reference to expected readings for different stages of sleep
• Describe how sleep diaries and video monitoring provide information about an individual's sleep
• Students will understand how sleep and its associated physiological responses are measured
• Sleep cycle


  An approximately 90-minute period that repeats during a sleep episode in which an individual progresses through stages of REM and NREM (stages 1-3) sleep
• Sleep-wake cycle


  A 24-hour cycle that is made up of time spent sleeping and time spent awake and alert
• Compare the terms 'sleep cycle' and 'sleep-wake cycle'.
• What patterns did you notice in your sleep diary?
• Do you think the data in your sleep diary is valid? Did you measure what you intended to measure?
• How could the sleep diary be improved? Or what would be a better way to gather this data?
• Biological rhythms

  Repeated biological processes that are regulated by internal mechanisms
• Ultradian rhythms

  Biological changes that occur in a cycle that lasts less than 24 hours
• Ultradian rhythms

  • Sleep cycle: an approximately 90-minute period that repeats during a sleep episode in which an individual progresses through stages of REM and NREM (stages 1-3) sleep
• Circadian rhythms


  Biological changes that occur as part of a cycle that lasts approx. 24 hours
• Circadian rhythms

  • Body temperature
  • The sleep-wake cycle: a 24-hour cycle that is made up of time spent sleeping and time spent awake and alert
• Light


  The main environmental cue that influences the sleep-wake cycle
• Suprachiasmatic nucleus (SCN)


  An area of the hypothalamus that receives information about the amount of light from the eyes, and regulates an individual's sleep-wake cycle accordingly
• The suprachiasmatic nucleus (SCN) is located above the optic chiasm (the intersection of the optic nerve fibres between each eye)
• The SCN also receives information from internal cues (e.g. expression and suppression of particular genes, known as clock genes)
• SCN


  Often called the 'internal body clock'