PSYC 100 Lecture Notes - Lecture 5: Atony, Brainstem, Dream Diary
Lecture 5
Tuesday, May 9, 2017
1:26 PM
Sleep & Consciousness
Consciousness
• Our subjective experience of our world, our bodies and our mental perspectives
• Consciousness exists on a spectrum
• Death -------- sleep -------awake
• State of awareness -of external events of your internal sensations and experiences
• Reacting to environment - conscious
• Take away point - hard to define consciousness
• Focus on altered types of consciousness
Sleep
• Temporary suspension of consciousness
• Composed of a series of precisely controlled psychological state
• Naturally occurring, periodic and recurring
• Involves the mind and body
• Sleep is not a passive state of unconsciousness
• Not a dissociation between brain and body
• Body works during our sleep
Why do we sleep?
Come back to these notes
Circadian Rhymes
• Cyclical changes that occur on a roughly 24h basis in many biological processes
(hormones, brain waves, body temperature, drowsiness)
• Biological clock - SCN in the hypothalamus
• Melatonin - hormone that triggers feelings of sleepiness
Other Rhythms
• Ultradian rhythms - cycles shorter than 1 day - hunger, eye blinks, heartbeats
• Infradian rhythms - cycles longer than 1 day - seasonal rhythms, breeding in animals,
female menstrual cycle
Jet Lag
• Results from disruption from your body's circadian rhythms
• Increases risk of injuries, accidents, health problems
• Important problem for travellers and shift workers
• Scientists are researching drugs that target melatonin receptors in the brain to re-synch
biological clocks
How to combat jet lag?
• Adjust bed time by 15 mins
• Seek bright light
Sleep Deprivation
find more resources at oneclass.com
find more resources at oneclass.com
• After a few nights leads to - depression, difficulties learning new information and paying
attention, slowed reaction times, hallucinations
• In the long term, associated with - weight gain, high BP, diabetes, heart problems, reduced
immune function
Peter Tripp
• World record for staying awake
• Used stimulants for last two days
• Reason he did this to raise money for a charity, broadcasted live for 11 days straight
How can you improve your sleep?
• Sleep hygiene - a variety of different practices and habits that are necessary to have good
night-time sleep quality and full daytime alertness
o Exercise, stay hydrated, stay cool, keep consistent sleep schedule, min. screen time,
"power down hour"
Measuring Sleep
• Behavioural studies
• Lesion studies
• Neuroimaging
o EEG - recording the brain's electrical activity at the surface of the skull
o PSG - recording various bio physiological changes that occur with sleep
• EEG - BRAIN WAVES
• EOG EYE MOVEMENTS
• EMG MUSCLE ACTIVITY
• ECG HEART RHYTHM
o MEG, fMRI, PET
Stages of Sleep
• Each night, we repeatedly pass through 5 stages
• Each sleep cycle lasts 90 mins
• Rapid eye movement REM - darting of the eyes underneath closed eyelids during sleep
• Non REM sleep - stages 1 - 4 of the sleep cycle
o No rapid eye movements
o Less frequent and less vivid dreaming
Stage 1 Sleep
• Light stage of sleep
• Lasts for 5-10 mins
• Brain produces theta waves 4-7Hz
o Slower than the beta waves of alert states (>13Hz) & alpha waves of relaxed states
(8-12 Hz)
• Hypnagogic imagery - scrambled, bizarre, and dream like images that flit and out of
consciousness
• Myoclonic jerks - sudden jerks of our limbs s if being startled or falling
Stage 2 Sleeps
• 65% of our sleep is spent in stage 2
find more resources at oneclass.com
find more resources at oneclass.com
29
PSYC 100 Full Course Notes
Verified Note
29 documents
Document Summary
Consciousness: our subjective experience of our world, our bodies and our mental perspectives, consciousness exists on a spectrum, death -------- sleep -------awake, reacting to environment - conscious, take away point - hard to define consciousness. State of awareness -of external events of your internal sensations and experiences. Sleep: temporary suspension of consciousness, composed of a series of precisely controlled psychological state, naturally occurring, periodic and recurring, not a dissociation between brain and body, body works during our sleep. Sleep is not a passive state of unconsciousness. Circadian rhymes: cyclical changes that occur on a roughly 24h basis in many biological processes (hormones, brain waves, body temperature, drowsiness, biological clock - scn in the hypothalamus, melatonin - hormone that triggers feelings of sleepiness. Other rhythms: ultradian rhythms - cycles shorter than 1 day - hunger, eye blinks, heartbeats. Infradian rhythms - cycles longer than 1 day - seasonal rhythms, breeding in animals, female menstrual cycle.
