Variations in Consciousness
The nature of Consciousness
Definition: Consciousness is the awareness of internal and external stimuli
- Is it passive (the receiver of sensation), or an active process like sensation and
Epiphenomenalism – the idea that mental states are born out or caused by physical states in
the brain. It’s the nervous system that gives rise to the consciousness. It
Variation in Levels of Awareness and Control
William James: Stream of conscious
Freud: influence of “unconscious” needs, wishes, and conflicts
“Level of awareness” (not an all-or-nothing thing): We are still conscious when asleep.
“Selective sensitivity” We can’t be conscious or aware of everything. Need to select to
function. i.e if we want to see something we need to fade out other things.
- There is active mental processing even when a sleep we don’t fall of bed when asleep
and we hear the cry of a baby but not the thunder storm.
Freud states that our mind tends to wander
Evolutionary Roots of consciousness
Allows for thought and making functional choices. Consciousness helps us make decisions
quickly. Consciousness and Brain Activity
Seems born out of the interplay of many different neural pathways
Brain Activity Can be Measured
- Summarizes the rhythm of cortical activity in the brain in terms of line tracins called
- Different pattrns with different states of consciousness exist.
Biological rhythms and sleep
(Many rhythms, ovarian cycle, cycles of the moon, biorhythms
Circadian Rhythms: Daily rhythms that our body tends to go through.
- Sleep debt
- Issue of shift work
Melatonin and Circadian Rhythms
Certain things reset the circadian rhythm every day for the 24 hour cycle
Conducting Sleep Research
Get set of instructions: (e.g. eat normal dinner, bring comfortable pajamas, avoid caffeine after
Sleep history: (e.g. how long does it take you to fall asleep? Once asleep, do you have trouble
staying asleep? Do you have any discomfort in your legs when you are lying in bed trying to
sleep? Do you snore? Do you fall asleep unintentionally during the day? (apnea, restless-leg
Hook up to: EMG (electromyography) and EOG (electrooculograph) (also measures for
breathing, heart activity, and smell activity) The Sleep Waking Cycle
Stage 1: alpha waves, hypnic jerks
Stage 2: sleep spindles
Stage 3 + 4: slow-wave sleep (SWS), delta waves
- It is hardest to wake up during REM
- Correlated with reports of vivid and m