PSYCH1000: CHAPTER 6: STATES OF CONSCIOUSNESS
The Puzzle of Consciousness
• Consciousness: moment-to-moment awareness of ourselves + environment
• subjective, dynamic, self-reflective, central to sense of self
• Helps us monitor & control / plan
• Selective attention focuses conscious awareness on some stimuli, excludes others
• Operationally defining states of consciousness
• Self-report, physiological, behavioural measures
• Freud’s levels of consciousness
• Preconscious: mental evenwts outside current awareness (easily recalled)
• Unconscious = cannot be brought into awareness under ordinary circumstances
• May “leak out” from time to time—> Freudian slip
• Unacceptable desires / repressed experiences
• Cognitive psychologists view unconscious as complimentary info-processor
• Daydreaming: safety valve, mood boost, low-risk way to deal w/ problems, increases arousal
• Failure/success, aggression, sex/romance, guilt, problem solving
• Controlled vs Automatic Processing
• Controlled: effortful, required to learn new tasks
• Automatic: little conscious effort, makes divided attention possible (“multitasking”)
• Emotional/motivational processes unconsciously influence behaviour
• Modular consciousness: separate but interacting info processors w/ an integrated output
Circadian Rhythms: Our Daily Biological Clocks
• CR= 24h biological cycles that regulate many bodily processes
• Body temp changes, hormone secretion from pineal gland, blood pressure
• Do not influence sleep directly (promote readiness for sleep)
• Internal timing controlled by SCN (suprachiasmatic nuclei) in hypothalamus
• Regularity of cycles impacted by environmental factors
• Daylight stimulates SCN —> production of melatonin inhibited
• Melanopsin: blue light (stimulates photosensitive ganglion cells)
• Personal CR determines morning vs night people
• Peak levels in late afternoon (best time for physical tasks)
• Circadian disruptions: seasonal depression, jet lag, night shiftwork
• Phase advance = more difficult than phase delay
• Treatments: exposure to light, oral melatonin, daily activity scheduling
Sleep
• Sleep regulated by brain stem & pons
• Study sleep using EEG (measures brain activity)
• Each sleep cycle lasts about 90 mins —> 123432REM
• Awake and alert: Beta waves (high frequency, low amplitude)
• Relaxed & drowsy: Alpha waves (frequency slows down)
• Stages of sleep
• 1) Light sleep, easily awakened: Theta waves increase (slower frequency)
• 2) Slightly deeper sleep: K-Complex (externally-triggered, big spike, develop later than SS)
followed by Sleep Spindles (periodic bursts of rapid brain activity)
• 3) Deeper sleep: Delta waves appear (low frequency, high amplitude)
• 4) Deep sleep: Delta waves dominate pattern
• REM: high physiological arousal, rapid eye movements
• Often remember dreaming when woken up during this stage
• EEG pattern resembles wakefulness
The Puzzle of Consciousness
• Consciousness: moment-to-moment awareness of ourselves + environment
• subjective, dynamic, self-reflective, central to sense of self
• Helps us monitor & control / plan
• Selective attention focuses conscious awareness on some stimuli, excludes others
• Operationally defining states of consciousness
• Self-report, physiological, behavioural measures
• Freud’s levels of consciousness
• Preconscious: mental evenwts outside current awareness (easily recalled)
• Unconscious = cannot be brought into awareness under ordinary circumstances
• May “leak out” from time to time—> Freudian slip
• Unacceptable desires / repressed experiences
• Cognitive psychologists view unconscious as complimentary info-processor
• Daydreaming: safety valve, mood boost, low-risk way to deal w/ problems, increases arousal
• Failure/success, aggression, sex/romance, guilt, problem solving
• Controlled vs Automatic Processing
• Controlled: effortful, required to learn new tasks
• Automatic: little conscious effort, makes divided attention possible (“multitasking”)
• Emotional/motivational processes unconsciously influence behaviour
• Modular consciousness: separate but interacting info processors w/ an integrated output
Circadian Rhythms: Our Daily Biological Clocks
• CR= 24h biological cycles that regulate many bodily processes
• Body temp changes, hormone secretion from pineal gland, blood pressure
• Do not influence sleep directly (promote readiness for sleep)
• Internal timing controlled by SCN (suprachiasmatic nuclei) in hypothalamus
• Regularity of cycles impacted by environmental factors
• Daylight stimulates SCN —> production of melatonin inhibited
• Melanopsin: blue light (stimulates photosensitive ganglion cells)
• Personal CR determines morning vs night people
• Peak levels in late afternoon (best time for physical tasks)
• Circadian disruptions: seasonal depression, jet lag, night shiftwork
• Phase advance = more difficult than phase delay
• Treatments: exposure to light, oral melatonin, daily activity scheduling
Sleep
• Sleep regulated by brain stem & pons
• Study sleep using EEG (measures brain activity)
• Each sleep cycle lasts about 90 mins —> 123432REM
• Awake and alert: Beta waves (high frequency, low amplitude)
• Relaxed & drowsy: Alpha waves (frequency slows down)
• Stages of sleep
• 1) Light sleep, easily awakened: Theta waves increase (slower frequency)
• 2) Slightly deeper sleep: K-Complex (externally-triggered, big spike, develop later than SS)
followed by Sleep Spindles (periodic bursts of rapid brain activity)
• 3) Deeper sleep: Delta waves appear (low frequency, high amplitude)
• 4) Deep sleep: Delta waves dominate pattern
• REM: high physiological arousal, rapid eye movements
• Often remember dreaming when woken up during this stage
• EEG pattern resembles wakefulness
