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sleep approximately every: ✔✔ 90 minutes
A study described in class showed that variation in the PER3 gene affected ✔✔ How individuals
reacted to sleep deprivation
Animals and sleep ✔✔ Mammals and birds all sleep. Horses sleep standing up, Dolphins and
porpoises sleep with one half of their brain at a time
Evolutionary explanation ✔✔ Sleep forces us to conserve energy at times when we would be
relatively inefficient
Predictions of an evolutionary theory ✔✔ Animal species should vary in the amount of sleep
they need depending on:
a) how much time they need to spend searching for food each day
b) how vulnerable they are to attack
Recuperation/repair theory ✔✔ Sleep deprivation should produce physiological and
psychological disturbances. These disturbances should get worse as deprivation continues. After
deprivation much of the sleep debt will be recovered. All vertebrates should sleep
Animal Studies- Sleep deprivation ✔✔ After 2 weeks unable to thermoregulate, lost weight,
infections.
After 4 weeks - death.
, As the sleeper progresses from stage 1 to stage 4 sleep ✔✔ The EEG becomes more
synchronised and of higher amplitude
What happens physiologically during a nights sleep? ✔✔ Electroencephalogram (EEG) gross
brain electrical activity
Electrooculogram (EOG) eye movements
Electromyogram (EMG) muscle tension
REM SLEEP (PARADOXICAL SLEEP) ✔✔ High correlation with dreaming
Common Beliefs about dreams ✔✔ External stimuli can be incorporated into dreams. Dreams
last only an instant Some people do not dream. Penile and clitoral erections indicate dreams
with a sexual content. Sleep walking and talking occur during dreams. Eye movements in REM
sleep relate to dream content
Declarative memory is enhanced by ✔✔ Early SWS sleep
Procedural memory is enhanced by ✔✔ Late REM sleep
If sleep is important for memory, is that reflected in changes in synaptic strength? ✔✔ Yes.This
process could underlie forgetting, however, since some evidence suggest that sleep improves
memory, it could also reflect the "removal" of meaningless connections in memory circuits thus
enhancing signal to noise.
Therefore, one essential function of sleep/dreaming may involve the consolidation of memories
Factors controlling sleep-wake regulation ✔✔ Factors controlling sleep-wake regulation Social
time, circadian, homeostat, light-dark cycle, biological time, sleep-wake cycle history