PSYC444 2025 UPCOMING MIDTERM 2 REVIEW
LECT NOTES WITH KEY CONCEPT (Sleep
Mechanisms and Behaviour) McGill University
Midterm 2 notes
MIDTERM 2 MATERIAL
Some new theories
REM sleep is needed to prevent the takeover of the occipital brain areas
during darkness
planetary adaptations - 24 hours etc, because weʼre stuck on this adaptations,
theres times when it is dark, at some point there is no visual input - during the
day - REM sleep is needed to prevent the takeover of the occipital brain areas
during darkness - to prevent us from not losing cognitive and perceptive skills
at night, youʼre still practicing it - if you donʼt use it youʼll lose it
Developmental shifts in function
,From reorganization to repair
Infants: more time in REM sleep, potentially different role of REM sleep
depending on age
Key Idea: sleep is for neural reorganizationuntil 2-3years of age, and then
sleep is for repair and clearance
By 2.4 years old: brains reach 80-90% adult size, white matter changes,
rapid growth of connectivity. Critical periods for many cognitive functions,
in particular acquisition of languag
, maybe different stages of sleep do different things depending on your
developmental stage at the moment, your sleep is serving the same funciton
as reogrnizing, neuroplasticity - when youʼre an adult, youʼre set, so for that
reason you donʼt need as much effort
because sleep is probably in control of regulating many of the functions, if you
donʼt sleep ^^
temporary sleep deprivation is fine, but chronic sleep deprivation accumulates
all of those side effects, but we canʼt tell who is more susceptible to these
effects
Effects of chronic sleep deprivation
Causes?
sleep disorders, modern work schedules (e.g. early work start), lifestyle
(e.g. Netflix)
Effects:
sleepiness, mood, impaired cognitive performance - driving safety!
, sleep deprivation is an amplifieer - if youʼre not sleeping you will amplify it
instead of diminishing it - chronic disease exacerbation - heart disease,
cardiovascular disease, diabetes…
depression and anxietyʼs symptoms get amplified if youʼre not getting
enough sleep
graph: fewer the
TIB - time in bed - if youʼre totally sleep deprived, you will have many more
lapses in
you will be less likely to respond to stimuli if youʼre completely sleep deprived
Effects of acute sleep deprivation
Randy Garner (stanford, sutdied by William Dement (father of contemporary
sleep research))
264.4 hours awake (11 days 25 minutes) (confirmed by EEG)
electrodes, brought a few friends there to keep him awake
in addition to cognitive symptoms (slow reaction time, forgetfulness,
inattention) - psychiatric symptoms
Early morning –the hardest (cuz of circadian rhythm - melatonin goes up)
4-5 days -ˮwaking dreamsˮ: decreased alertness, possibly microsleeps (what
causes car crashes)
Suspiciousness, resentment
Fleeting disorientation in time
Body sensations: burning eyes, heaviness, fatigue
became paranoid, resentful, delusional, disoriented in time, hallucinations
11 days after - recovery night
LECT NOTES WITH KEY CONCEPT (Sleep
Mechanisms and Behaviour) McGill University
Midterm 2 notes
MIDTERM 2 MATERIAL
Some new theories
REM sleep is needed to prevent the takeover of the occipital brain areas
during darkness
planetary adaptations - 24 hours etc, because weʼre stuck on this adaptations,
theres times when it is dark, at some point there is no visual input - during the
day - REM sleep is needed to prevent the takeover of the occipital brain areas
during darkness - to prevent us from not losing cognitive and perceptive skills
at night, youʼre still practicing it - if you donʼt use it youʼll lose it
Developmental shifts in function
,From reorganization to repair
Infants: more time in REM sleep, potentially different role of REM sleep
depending on age
Key Idea: sleep is for neural reorganizationuntil 2-3years of age, and then
sleep is for repair and clearance
By 2.4 years old: brains reach 80-90% adult size, white matter changes,
rapid growth of connectivity. Critical periods for many cognitive functions,
in particular acquisition of languag
, maybe different stages of sleep do different things depending on your
developmental stage at the moment, your sleep is serving the same funciton
as reogrnizing, neuroplasticity - when youʼre an adult, youʼre set, so for that
reason you donʼt need as much effort
because sleep is probably in control of regulating many of the functions, if you
donʼt sleep ^^
temporary sleep deprivation is fine, but chronic sleep deprivation accumulates
all of those side effects, but we canʼt tell who is more susceptible to these
effects
Effects of chronic sleep deprivation
Causes?
sleep disorders, modern work schedules (e.g. early work start), lifestyle
(e.g. Netflix)
Effects:
sleepiness, mood, impaired cognitive performance - driving safety!
, sleep deprivation is an amplifieer - if youʼre not sleeping you will amplify it
instead of diminishing it - chronic disease exacerbation - heart disease,
cardiovascular disease, diabetes…
depression and anxietyʼs symptoms get amplified if youʼre not getting
enough sleep
graph: fewer the
TIB - time in bed - if youʼre totally sleep deprived, you will have many more
lapses in
you will be less likely to respond to stimuli if youʼre completely sleep deprived
Effects of acute sleep deprivation
Randy Garner (stanford, sutdied by William Dement (father of contemporary
sleep research))
264.4 hours awake (11 days 25 minutes) (confirmed by EEG)
electrodes, brought a few friends there to keep him awake
in addition to cognitive symptoms (slow reaction time, forgetfulness,
inattention) - psychiatric symptoms
Early morning –the hardest (cuz of circadian rhythm - melatonin goes up)
4-5 days -ˮwaking dreamsˮ: decreased alertness, possibly microsleeps (what
causes car crashes)
Suspiciousness, resentment
Fleeting disorientation in time
Body sensations: burning eyes, heaviness, fatigue
became paranoid, resentful, delusional, disoriented in time, hallucinations
11 days after - recovery night
