Why do we Sleep and Dream 2 Flashcards
SCN and Biorhythms effect our ____ _____ memory
state dependant
2 general ways to measure sleep
self report
laboratory
what is used to measure the electrical activity of the brain
polygraph
an instrument for recording variations of several different physiological pulsations simultaneously
polygraph
- record of brain wave activity
- record of muscle activity
- record of eye movement
- electroencephalogram
- electromyogram
- electrooculogram
4 stages of sleeping and waking
- Beta rhythm (waking state)
- Alpha rhythm (relaxed state)
- Theta rhythm (drowsy state)
- delta rhythm (sleeping state)
small amplitude, fast frequency, (15-30hz); muscle tone; eyes move
beta rhythm
large amplitude, slow frequency (7-11), muscle tine, eyes closed
alpha rhythm
EEG waves increase, slower frequency (4-7), muscle tone, eye NOT moving
theta rhythm
slow, large EEG waves (1-3 hz), associated with loss of consciousness; muscle tone, no eye movement
delta rhythm
fast brain wave pattern displayed by the neocortical EEG record during sleep: muscle inactivity (atonia) except for twitches and eye movements
REM sleep
delta rhythm, EEG oattern in slow and large and EOG in inactive
nonREM
what happens to body temp during sleep
declines
what is a typical nights sleep in regard to stages?
awake
non rem (90 min cycle)
stage 1
stage 2
stage 3
stage 4
rem
after REM we loop back to what stage
stage 2
when is our lowest body temp during sleep
during earlier NREM sleep and rises in the later REM dominated parts
what stage do we spend the longest in in one cycle
stage 4
adults who sleep 8 hours spend ___ hours in REM
2
duration of REM varies with ____ and changes dramatically over the life span
- when is REM high?
- when does it increase?
age
- infancy
- growth spurts, physical exertion, pregnancy
- decrease in body temp, increase in GH release
- talk or grind teeth
- flailing, banging arm, kicking
NON rem sleep
in NON REM sleep we maintain ?
muscle posture
dreaming occurs in nrem sleep but not as vivid as in rem sleep,
except for ? (3)
sleep walking
sleep talking
night terrors
REM sleep you have atonia which is ?
no ton, condition of complete muscle inactivity produced as sleep regions of our brainstem inhibit motor neurons
in REM sleep, mechanisms that regulate ___________ stop working
- causing?
body temperature
- body temp to move toward room temp
neural pathways that mediate this are spared paralysis during rem sleep
distal twitches
2 theories for twitching
maintain blood flow
neural development and fine tuning of coordinated movements
does everyone dream every night
yes, a number of times
in REM sleep, dreams appear to take place where? and dream sessions get longer?
- in real time
- longer throughout a sleep session
breif frightening dreams which occur in NREM sleep
night terrors
sigmund freud dream theory
dreams are the fullfillment of unconscious wishes
- manifest content: loosely connected series of bizarre images and actions
- latent content: true meanign of the dream
carl jung dream theory
dreams are expansions of memories that have lost connection to consciousness—- dreams allow the dreamer to relive “collective unconscious”
what are 2 problems with dream theories
- it is impossible to know the “correct: interpretation
2. biased methods
contemporary methods of dream theory focus on the objective
- most dreams are related to?
quiet events and concern on going problems
out of 10 000 dreams of a healthy individual:
- 64% associated with
- 18% associated with
- 1% associated with
- sadness, anxiety , anger
- happiness
- sexual acts or feelings
2 approaches to contemporary thoughts on what we dream
bottom up: no meaning in dreams, person dreasm then the dreamer analyzes it
top down: content of the dream reflect biological adaptive mechanism- the dreamer makes the dream
the cortex is bombed with signals from the brainstem, producing a pattern of waking EEG
- in response the cortex generate images, actions and emotions from personal memory stores
- what theory ?
activation - synthesis hypothesis (dreams are meaningless brain activity )
J. Allan Hobson
dreams are highly organizes and biased toward threatening images
- they are biologically important becuase they lead to enhanced performance in dealing with threatening life events
- what theory
evolutionary dream hypothesis
- dreams as coping strategy
Antonia Revonsuo
extension of the top down theory, people are problem solvers when awake and that continues during sleep
evolutionary hypothesis
dreams as a coping strategy
do ppl sleep less or more in isolation
less (sleep is not a result of decreased sensory stimulation)
3 main contemporary explantations for sleep
- sleep is adaptive
- sleep is restorative
- sleep is supportive of memory
3 facts that support that sleep is a biologically adaptive behaviour that influences the ways species have evolved to interact with its environment
- sleep is an energy conserving strategy : gather food at optimal times
- predatory animals sleep more than prey animals
- nocturnal or diurnal animals will sleep when they cannot travel easily
what animal sleeps the less? and the most?
donkey (4 hour), opossum (20hour)
3 ways that sleep conserves energy
- energy not being expended
- switching the brain off, especially in nrem sleep
- decline in body temp decrease the bodys metabolism
recurring cycles of temporal packets, about 90 min periods of humans, during which animals level of arousal waxes and wanes
- examples?
basic rest-actvity cycle (BRAC)
- school classes, work periods, meal time, coffee or snack breaks
does the BRAC turn off at night?
no. the body is paralyzyed during rem sleep to prevent interruptions thorughout sleep
our behaviour is dominated by ______ through which our activity levels change in the course of the day and by an NREM and REM sleep cycle during the night
BRAC
chemical events that provide energy to cells may be reduced during waking and are replenished during sleep
- evidence of?
sleep as a restorative process
what is the thought that sleep might not be a restorative process?
fatigue and alertness may simply be aspects of the circadian rythms and have nothing to do with wear and tear on the body
how do they test if sleep is a restorative process
sleep deprivation
- found it does not cause physiological changes but cognitive deficits
- hard to test because ppl micro sleep (confounding factor)
cognitive tasks that require ______ declines as a function of hours of sleep deprivation
attention
in animals, complete sleep deprivation with no micro sleeps has been associated with
death
in sleep studies ppl who were deprived had an increased tendency to?
- what is the rem rebound that was also found
enter REM sleep in subsequent sleep sessions
-and they spend more time in REM sleep in the first available sleep session
what are 2 facts that provide evidence that REM deprivation is not associated with adverse effect
- antidepressants decrease REM - no adverse consequences
2. brainstem damage can result in complete loss of REM sleep without any apparent ill effects
sleep _______ and _________ memory
- theory is over ___ years old
- solidifies and organizes
- 100 years
3 phases of memory storage
- Labile Phase: memory is fragile and must compete with existing memories and addition of new memories
- Consolidation Phase: forges a relatively permanent representation of the memory; biochemical and genetic activity lead to structural changes
- Recall Phase: put the memory to work at some future time and also integrates it in to exsisting memory stores
3 main theories of sleep and memory storage
- multiple process theory
- sequential process theories
- storage process theories
different kinds of memory ares stored during different sleep states
multiple process theory
memory is manipulated in different ways during different sleep states (one stage erases old competing memories, another stores new)
sequential process theories
brain regions that handle different kinds of memory during waking continue to do so during sleep. sleep = no competitions from new working experiences (incoming stimuli)
storage process theories
what happens with experiences during NREM sleep
they are being replayed and stored
what did researchers find with the firing of place cells (hippocampal neural activity) when rats slept, searched for food, and during NREM sleep after food search
the same cells fired during the food search and after the food search in NREM sleep (consolidation)
when having participant complete serial reaction time tasks,PET imaging showed
same brain regions were active during the task and during REM sleep (they were dreaming about what they learned)
explicit memory is stored during ____ sleep and implicit memory is stored during ______
- NREM
- REM
melatonin might be thought to be sleep producing substance; however, sleep persists even with the removal of the pineal gland
– what does this mean?
- substances appear to support but not cause sleep
hemispheric sleep (dolphins and birds) suggest sleep is produced by?
the action of some brain region
large reticulum that runs through the center of the brain stem
reticular activating system
RAS is a mixture of
nuclei and nerve fiber
stimulating the RAS produces?
damage to the RAS produces?
- waking EEG
- slow wave EEG
damage to what area can result in coma
reticular activating system
if incoming sensory pathways to the RAS are cut we still ?
produce a waking EEG
the RAS is the ______ of waking and ________ stimulation produces waking because it activates _____ -_______
source, sensory, RAS neurons
the RAS is a ____ _____ to the SCN
slave ocsillator
2 brainstem systems that influence waking
- basal forebrain
2. median raphe nucleus
what does the basal forebrain do in waking behaviour
contains cholinergic cells that secrete Ach onto neocortical neurons that stimulate a waking EEG (beta) rhythm
what dos the median raphe nuclues do in waking behaviour
contains serotonin neurons that project diffusely to the neocortex; also stimulates beta rhythms
cholinergic pathway (ACh from basal forebrain) is activated when we are ? and the serotonergic system (raphe) is activated when we ?
- awake but not moving
- are moving
damage to basal forebrain and/or the median raphe nucleus results in ?
an EEG that permanently resembles that of a sleeping animal (but can still walk around) (they dont produce bahaviour) (wont be abel to display intelligent behaviour or learn things if damage both)
RAS produces its arousal effect by influencing?
the activity of basal forebrain and median raphe nucleus pathways
cholinergic nucleus in the dorsal brain stem has a role in REM sleep behaviours; projects to the medial pontine reticulum
peribrachial area
initiates REM sleep and REM related behaviours
peribrachial area (RAS is still central producer of REM sleep)
nucleus in the pons participating in REM sleep
- projects to several other brain area that produce REM related behaviours
medial pontine reticular formation
produces the atonia of REM SLEEP
medial pontine reticular formation
the _______ is involved in a complex series that helps explain how REM event, rapid eye movements, and atonia take place in the absence of muscle tone
peribrachial area * draw this pathway
2 most common NREM sleep disorders
- insomnia
2. Narcolepsy
what is insomnia
disorder of slow wave sleep resulting in prolonged inability to sleep
_____ and ______ account for 35% of insomnias
and _____ accounts for 15%
anxiety and depression
- worrying about insomnia
what are drugs that help insomnia risky
develop dependancy insomnia
what is narcolepsy
slow wave disorder in which a person uncontrollably fall asleep at inappropriate times
what kind of drugs are helpful for narcolepsy
drugs that stimulate dopamine transmission
what is one concerning cause of narcolepsy
sleep apnea (inability to breath during sleep)
sleep apnea can be cause by ?
and can cause?
- weak neural command or can be obstructive (collapse of upper airway caused by snoring or obesity)
- high blood pressure, CVD disease, memory problems, weight gain, impotence, headaches, and brain damage due to hypoxemia
atonia and dreaming when a person is awake, usually just falling asleep or waking up
(partial REM sleep)
sleep paralysis
what 3 feelings do people with sleep paralysis experience
- a presence in the room
- something pressing on their chest
- feeling of levatation
what is catalepsy
a form of narcolepsy in which a person loses all muscle activity or tone, as if in REM sleep, while awake (strongly linked to emotions)
cataplexy; you experience ______ ________ –> a dreamlike event at the beginning of sleep or while a person is in a state of cataplexy
hypogenic hallucination
_____ loss is related to cataplexy, which normally plays a role in?
- orexin
- maintaining activity during waking
______ cell sin the hypothalamus send projections to many other brain regions, as do nonspecific activating systems using ______ and ________
- orexin
- ACH
- serotonin
ppl who have _____ behave as though hey are acting out their dreams
REM sleep behaviour disorder
REM sleep behaviour disorder affects some ppl taking?
and can be treated with?
antidepressants
- benzodiazepines, antianxiety drugs that block REM sleep
studying sleep and sleep related disorders may help us to understand the >
neural basis or consciousness
