Chapter 5: Variations in Consciousness
Consciousness: awareness of internal/external stimuli, (self and thoughts), involves various
levels of awareness/alertness (measured by an EEG), subjective, private, dynamic,
continually changing
External stimuli
Internal stimuli
Biological Rhythms: periodic fluctuations in physiological functions tied to planetary
rhythms
Circadian Rhythms: 24-hour cycles that are influential in the regulation of sleep
Internal biological clocks are reset by exposure to light, stimulating the SCN in the
hypothalamus, genetically
programmed: affected by air travel (jet
lag), shift work (mood, could cause
accident), daylights savings, illness,
drugs, exercise, fatigue (stress)…
Suprachiasmatic nucleus:
regulates melatonin levels
Seasonal Affective Disorder (SAD):
cyclic tendency to become psychologically depressed during certain months (lower levels of
light influence mood?)
Dreams:
Theories: Freud thought that the goal of dreams is wish fulfilment; other theorists
argue that dreams provide an opportunity to think creatively about personal problems; the
activation-synthesis model proposes that dreams are side effects of the neural activation that
produces walking-like brain waves during REM sleep.
Why do we dream?
Sigmund Freud: wish fulfillment
psychoanalytic theory (form of psychotherapy), royal road to the unconscious, wish
fulfillment, manifest and latent content (manifest is what you would report, latent is the true
meaning; how do you bring these into a lab for study?)***, dream work, dream interpretation
Believed that the mind was a battle ground full of dark things, sexual and aggressive
content buried outside of level of awareness (unconscious) , conscious mind contains info
which we are currently aware,
preconscious (info readily accessible but
not thinking of it currently)
Dreams are ‘royal road to the
unconscious’, providing glimpse into that
world, wish fulfillment (sexual impulses),
mind disguises impulses in order to not
cause anxiety
More theories:
Problem focused (Cartwright): represent
, preoccupation of waking life, influence dream stories
Information processing (Hobson): consolidation, we dream to remember and forget,
use dream space to engage pruning, strengthen neuroconnections used throughout the day/
synaptic connections associated with recently stored memories (consolidation), promoting
connections used, eliminating unnecessary neural connections
Activation Synthesis (Hobson and McCarley): spontaneous firing of neurons in pons,
cerebral cortex synthesizes signals and tries to interpret them, prefrontal cortex (executive
motions like logical and reason) is not peaking/suppressed functioning while sleeping
Dreams Miscellany
If awakened during REM, 70% report dreaming in vivid colour, 13% in vague colour
Outside of the lab, majority report dreams are colourless
Sleep:
Nathaniel Kleitman: father of modern sleep research, first to conduct systematic sleep
investigations using EEG machines, established key methods of data gathering
Amplitude: height
Frequency: cycle
Ex: low amplitude high frequency: beta and alpha waves
Stage 1, Theta waves: things are slowing down (dozing)
Stage 2: very light sleep, awoken easily (sleep spindle: burst of activity)
Stage 3: start of delta waves, higher amplitude and lower frequency, difficult to awaken
Stage 4: very deep sleep, entire delta waves, very difficult to awaken
non-REM sleep: marked by an absence of rapid eye movements, little dreaming and varying
EEG activity
REM sleep: deep stage of sleep marked by rapid eye movements, high-frequency brain
waves and dreaming, eyes move rapidly back and forth
● Paradoxical sleep
● Physiological changes: genitals to enlarge/become engorged with blood
● REM paralysis: lose voluntary muscle control, frozen when trying to move, in
process of awakening
● Dream issues
● REM rebound
More REM the younger you are
(growth hormones released during
this stage)
Ascending reticular activating
system (ARAS) consists of the
afferent fibres running through the
reticular formation that influence
physiological arousal
Hypnic jerks: brief muscular
Consciousness: awareness of internal/external stimuli, (self and thoughts), involves various
levels of awareness/alertness (measured by an EEG), subjective, private, dynamic,
continually changing
External stimuli
Internal stimuli
Biological Rhythms: periodic fluctuations in physiological functions tied to planetary
rhythms
Circadian Rhythms: 24-hour cycles that are influential in the regulation of sleep
Internal biological clocks are reset by exposure to light, stimulating the SCN in the
hypothalamus, genetically
programmed: affected by air travel (jet
lag), shift work (mood, could cause
accident), daylights savings, illness,
drugs, exercise, fatigue (stress)…
Suprachiasmatic nucleus:
regulates melatonin levels
Seasonal Affective Disorder (SAD):
cyclic tendency to become psychologically depressed during certain months (lower levels of
light influence mood?)
Dreams:
Theories: Freud thought that the goal of dreams is wish fulfilment; other theorists
argue that dreams provide an opportunity to think creatively about personal problems; the
activation-synthesis model proposes that dreams are side effects of the neural activation that
produces walking-like brain waves during REM sleep.
Why do we dream?
Sigmund Freud: wish fulfillment
psychoanalytic theory (form of psychotherapy), royal road to the unconscious, wish
fulfillment, manifest and latent content (manifest is what you would report, latent is the true
meaning; how do you bring these into a lab for study?)***, dream work, dream interpretation
Believed that the mind was a battle ground full of dark things, sexual and aggressive
content buried outside of level of awareness (unconscious) , conscious mind contains info
which we are currently aware,
preconscious (info readily accessible but
not thinking of it currently)
Dreams are ‘royal road to the
unconscious’, providing glimpse into that
world, wish fulfillment (sexual impulses),
mind disguises impulses in order to not
cause anxiety
More theories:
Problem focused (Cartwright): represent
, preoccupation of waking life, influence dream stories
Information processing (Hobson): consolidation, we dream to remember and forget,
use dream space to engage pruning, strengthen neuroconnections used throughout the day/
synaptic connections associated with recently stored memories (consolidation), promoting
connections used, eliminating unnecessary neural connections
Activation Synthesis (Hobson and McCarley): spontaneous firing of neurons in pons,
cerebral cortex synthesizes signals and tries to interpret them, prefrontal cortex (executive
motions like logical and reason) is not peaking/suppressed functioning while sleeping
Dreams Miscellany
If awakened during REM, 70% report dreaming in vivid colour, 13% in vague colour
Outside of the lab, majority report dreams are colourless
Sleep:
Nathaniel Kleitman: father of modern sleep research, first to conduct systematic sleep
investigations using EEG machines, established key methods of data gathering
Amplitude: height
Frequency: cycle
Ex: low amplitude high frequency: beta and alpha waves
Stage 1, Theta waves: things are slowing down (dozing)
Stage 2: very light sleep, awoken easily (sleep spindle: burst of activity)
Stage 3: start of delta waves, higher amplitude and lower frequency, difficult to awaken
Stage 4: very deep sleep, entire delta waves, very difficult to awaken
non-REM sleep: marked by an absence of rapid eye movements, little dreaming and varying
EEG activity
REM sleep: deep stage of sleep marked by rapid eye movements, high-frequency brain
waves and dreaming, eyes move rapidly back and forth
● Paradoxical sleep
● Physiological changes: genitals to enlarge/become engorged with blood
● REM paralysis: lose voluntary muscle control, frozen when trying to move, in
process of awakening
● Dream issues
● REM rebound
More REM the younger you are
(growth hormones released during
this stage)
Ascending reticular activating
system (ARAS) consists of the
afferent fibres running through the
reticular formation that influence
physiological arousal
Hypnic jerks: brief muscular
