5.1 What is Consciousness?
Consciousness: moment-by moment subjective experiences. Descartes: mind separate from brain (dualism).
Most psychologists believe brain and mind inseparable: neurons activity in braincontents of consciousness,
for each type of content (sight, smell) there is associated pattern of brain activity; activation of particular
group of neurons in brainconscious experience, subjective nature makes it difficult to study empirically.
Variations in conscious experience: limit to how many things mind can be conscious of at same time. Level of
consciousness varies through day, affected by actions/substances. Everyone executes automatic tasks and
controlled processing. Consciousness’ 3 roles: complex actions requiring input from different brain regions,
connecting with one another, complicated thinking.
o Extreme states: coma: people still have sleep/wake cycles, do not respond, although brain sometimes
can process info. Persistent vegetative state - no consciousness because no normal brain activity.
Between vegetative state/consciousness is minimally conscious.
Brain activity consciousness: consciousness, mental states can be examined/measured, eg relationship btwn
consciousness, neural responses in brain; particular type of neural activity particular type of awareness
o Global workspace model: consciousness arises as function of which brain circuits are active – you
experience brain regions’ output as conscious awareness. No single area responsible for awareness;
different areas deal with different types of info, each system responsible for consciousness awareness
of its type of info. Consciousness makes us actively aware of info, prioritizes what info we need/use
o Split brain: corpus callosus cut, two hemispheres do not receive info directly from each other.
o Interpreter: L hemisphere’s attempts to make sense of actions and ongoing events
o Interpreter speculates: strongly influences way we view/remember world, tends to “compress”
experiences into story. Right brain experiences world, remember things with less narrative
interpretation. Left hemisphere interpreter searches for patterns that might not even exist.
Unconscious processing influences behavior: we are aware of some mental processes but not others.
Subliminal perception: processing of info by sensory systems without conscious awareness, used in ads
o Smart unconscious: not consciously thinking can produce a superior outcome to consciously thinking.
Consciously thinking can undermine good decision making
5.2 What is sleep? Brain does not shut down; regions active during sleep, e.g. complex thinking. Circadian rhythms:
regulation of bio cycles into regular patterns, “about a day,” temp, hormones, sleep/wake cycles. Suprachiasmatic
nucleus: in hypothalamus, gets info about light, sends signals to pineal gland, may secrete melatonin (suppressed by
bright light, triggered in dark). SLEEPLESS gene regulates protein that reduces action potential in brain
Sleep is altered state of consciousness: not fully conscious, but aware of surroundings, brain processes info.
EEG shows beta waves appear when people are awake/neurons active, alpha waves when focused or relaxed
o Stages of sleep: 1: theta waves, light sleep. 2: regular breathing, less sensitive to stimulation, sleep
spindles and K-complexes. 3 and 4: delta waves, slow-wave sleep.
o REM: after 90 min, cycle reverses to stage 1, EEG shows beta waves, rapid eye movements, dreaming
occurs, muscles paralyzed. Short cyclemore REM sleep as night progresses.
o Sleep disorders: insomnia: mental health, ability to function compromised by inability to sleep
diminished psyc well-being. Pseudoinsomnia; dreaming you are not sleeping. Obstructive sleep
apnea: throat closesfrequent awakenings, aided by CPAP. Narcolepsy: excessive sleepiness,
involves muscle paralysis. REM behavior disorder: no paralysis. Somnambulism: sleepwalking
Sleep is an adaptive behavior: why waste time?
o Restoration and sleep deprivation: sleep allows body and brain to rest, repair. Deprivationmood and
cognitive problems, attention lapses, reduced short-term memory, immunity problems, microsleeps.
o Circadian rhythms: sleep has evolved to keep us quiet, inactive during time of greatest danger.
o Facilitation of learning: sleep involved in strengthening of neural connections that serve as basis of
learning. Circuits wired together during wake are consolidated during sleep, especially if you dream
(REM sleep promotes development of brain circuits for learning, e.g., exam periods and infants)
People dream while sleeping: products of altered state of consciousness, images confused with reality.
o REM dreams and non-REM dreams: REM dreams more bizarre, intense emotions, hallucinations,
acceptance of illogical events. Non-REM dreams du