SLEEP. Dement and Kleitman (1930’s). Qu. How do we measure sleep?. Electro-encephalogram ( Head ) Electro-oculogram( Eye ) Electro-myogram( Neck ). EEG TODAY. Brain Waves and Sleep Stages. Awake. 1. 2. 3. REM. 4. 0. 1. 2. 3. 4. 5. 6. 7. Hours of sleep.
Dement and Kleitman (1930’s)
Qu. How do we measure sleep?
Hours of sleep
Restoration Model = Sleep allows us to recharge our bodies and recover from fatigue
Evolutionary/circadian rhythm model Sleep’s main purpose is to increase a species’ chances of survival
Following sleep deprivation, we recover much of our lost sleep but there is some segregation of recovery of different types of sleep.
Following selective SWS or REM deprivation, there is selective recovery
Qu. If the body can repair itself under a wakeful state, what is the main purpose of sleep, physiological repair or neurotransmitter recovery?
Qu. If REM is for neurotransmitter recovery, why do infants spend 50% of their sleep in REM, but by the first year they have half of that (when most learning occurs)?
Evolutionary/circadian rhythm model
Sleep’s purpose = increase the chances of survival
Species sleep patterns are different due to….
Qu. Do all animals sleep?
All mammals and birds sleep.
Qu. Can you explain these differences?
Fish, reptiles and amphibians have periods of ‘inactivity’
SWS and REM sleep patterns in mammals
Qu. What would happen to the sleep patterns of animals who can function at night?
Strickgold (1999) found that PET scans reveal a high level of activity between these two structures during sleep.
SWS - activity is one way
REM - info flows other way