Psychology 1000 Lecture Notes - Lecture 6: Circadian Rhythm, Jet Lag, Sleep Deprivation

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2 Aug 2016
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-Circadian rhythms
-Sleep stage
Next time: Dreams
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What are the daily rhythms affecting humans?
What is consciousness?
What happens when we sleep?
Circadian rhythms
-Daily cycles
-Blood pressure
-Body temperature
-Chemical concentrations
-25 hour “clock”
-Peak levels= in late afternoon (best time for physical tasks)
-Suprachiasmatic nucleus
(area of the brain that controls this)
Bundle of cells above optic chiasm
-Internal timing mechanism in hypothalamus
-Daylight stimulates the SCN which inhibits production of melatonin in pineal gland
-Darkness removes the inhibition, resulting in more melatonin…we feel tired
-Jet lag and shift work
-Phase advance more difficult than phase delay ex. Flying from Vancouver to Halifax is more
problematic than east to west
How to fix it
-Take melatonin?
-Doesn’t really work
-Seems safe
-More effective for delay than advance (unhelpful)
-Probably works by relieving daytime fatigue
Avoiding jet lag
-Hydrate on plane
-Avoid alcohol
-Get up and stretch
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-Light meals
-Exposure self to sunlight upon arrival
-Awareness of the relationship between self and the external world
-Monitoring- keeping track of self
-Control- planning
Preconscious level
-Info not currently available but could be
-Not always thinking about it, you have to search for it
-What does your parents’ house look like?
-Tip of the tongue
Subconscious level
-Info not accessible
-From time to time information might leak out
-Freudian slips= unconscious leakage
Freud= A happy person never fantasizes about things only an unhappy one does
Top 5 daydreams (occurs roughly very 90 mins)
1. Failure or success
2. Aggression
3. Sex or romance
4. Guilt
5. Problem solving
Why daydream
-Safety values
-Escape from life
-Alters mood in positive direction
-Low risk way to deal with problems (imagine reality)
-Increase arousal
Stages of sleep
During sleep the body begins to shut down
-Heart rate is lowered
-Respiration lowered
-Minimum of muscle activity
-Temperature drops (kicks off onset of sleep cycle)
-Marked decrease in sensitivity to external stimulation
EEG recordings
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Stage 1
-Sensitive to external world
-Easily awakened
-Theta waves
Stage 2
-Sleep spindle
-Burst of activity
-Prepatory pattern for memory storage
-K complex
-Large intense wave
-Can induce seizures
-Related to RLS and Epilepsy
Stage 3
-40-45 mins into sleep
-Introduction of delta waves
Stage 4
-Deepest stage
-Only delta waves
-After stage 4 cycles reverse, when you go back into stage 1 you go into REM sleep
REM sleep
-Rapid eye movement sleep
-Theta and Beta waves
-Brain pattern looks like your awake (resembles being awake)
-After REM stage you go back through the cycle
-Go through cycle 5-6 times in a night
Why do we sleep?
-Restorative function
-Store what we did during the day
-Sleep deprivation= attention lapse and irritability
-Little effect on task performance
-Evolutionary benefit
-Being outside the cave at night was dangerous, genes passed on
-Learning and memory
-REM deprived subjects show reduced ability to retain new information
-Note: REM specific
-Mood adjustment
-Speed of cycling into REM correlated with positive mood on the following day
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