sleep Flashcards
(120 cards)
1
Q
what is sleep?
A
sleep is a regulated behaviour
2
Q
what is sleep vital for?
A
normal functioning
health
well being
memory
3
Q
where is sleep research conducted?
A
in a sleep laboratory
4
Q
what do researchers interested in sleep measure?
A
EEG
EMG
EOG
heart rate, respiration, skin conduction
5
Q
EEG
A
electroencephalogram- brain activity
6
Q
EMG
A
electromyogram - muscleactivity
7
Q
EOG
A
electro-oculogram
eye movements
8
Q
what are teh two basic patterns of brain activity during wakefulness?
A
beta activity and alpha activity
9
Q
beta activity frequency range
A
13-30 Hz
10
Q
beta activity
A
alert, attentive, active thinking
many different neural circuits in teh brain are actively processing information
11
Q
alpha activity frequency
A
8-12 Hz
12
Q
alpha activity
A
resting quietly
not aroused or excited
not engaged in strenuous mental activity
usually occurs when eyes are closed
13
Q
theta activity
A
3.3-7.5 Hz
stages 1 and 2
REM
14
Q
delta activity
A
<3.5 Hz
stages 3 and 4
15
Q
what happens as sleep deepens
A
frequency of brain activity decreases
16
Q
stages of sleep in order
A
wakefulness stage 1 stage 2 REM stage 3 stage 4
17
Q
stage 1 sleep
A
transition between sleep and wakefulness (drowsy)
18
Q
how long does stage 1 sleep last
A
approx 10 mins
19
Q
EEG during stage 1 sleep
A
firing of neurons in the neocortex become more synchronised
20
Q
stage 2 sleep
A
if people awakened, they may report that they have not been asleep
21
Q
how long does stage 2 sleep last?
A
approximately 15 minutes
22
Q
EEG stage 2
A
irregular
sleep spindles
k complexes
23
Q
sleep spindles
A
short bursts of waves 12-14 Hz
occur between 2 and 5 times a minute during sleep stages 1-4
24
Q
what are increased numbers of sleep spindles associated with?
A
higher scores on intelligence test
25
k complexes
sudden sharp waveforms usually only found in stage 2
associated with a consolidation of memories
forerunner of deltawaves
26
stages 3 and 4 are called?
slow wave sleep
27
stage 3 & 4
only loud noises will wake people up
| when awakened, the person acts groggy and confused
28
distinction between stage 3 and stage 4
stage 3: 20-50% delta activity
| stage 4: over 50% delta activity
29
slow wave oscillations, frequency and types?
```
most important feature of slow wave sleep
<1Hz
down state (off)
up state (on)
moderate muscle tonus
slow or absent eye movements
```
30
down state (off)
neurons in the cortex are absolutely silent - neurons are able to rest
31
up state (on)
period of excitation during which these neurons briefly fire at a high rate
32
REM sleep EEG
desynchrony
| rapid, irregular
33
physiological changes associated with REM
rapid eye movements
profound loss of muscle tone- paralysis
mechanisms that regulate body temperature stop working
brain is active: cerebral blood flow and consumption are accelerated
34
REM sleep
we dream
people react to meaningful stimuli (e.g. name)
if woken the person will usually appear attentive and alert
35
when do humans sleep with only one hemisphere of their brain?
first night effect
36
first night effect (FNE)
troubled sleep in a novel environment
| one hemisphere being more vigilant than the other to monitor unfamiliar surroundings during sleep
37
functions of slow wave sleep
allows the brain to rest
38
how does slow wave sleep allow the brain to rest?
cerebral metabolic rate and blood flow falls by about 75%
| suggested that the cerebral cortex shuts down during sleep
39
why is it suggested the cerebral cortex shuts down in stage 3&4
reduced metabolic rate and blood floe
peoples unresponsiveness
confusion if awakened
40
what does slow wave sleep deprivation effect?
cognitive abilities, especially sustained attention, but not physical abilities
41
is sleep related to exercise?
the amount we exercise in a day does not affect the amount we sleep
42
rebound phenomenon:
if deprived of REM sleep you will have more REM sleep in the next period
43
is it possible to function with no REM sleep?
yes, with no side effect s
| this is shown by people on antidepressants or with brain damage that reduces or eliminates REM sleep
44
possible functions of REM sleep
promotes learning
| brain development
45
REM sleep and brain development
facilitates massive changes in the brain
| highest proportion of REM sleep occurs during brain development
46
criticism against link between REM and brain development
adults still have REM sleep
47
two broad types of memory
declarative and non declarative (explicit and implicit)
48
Mednick, Nakayama, & Stickgold (2003) method
Participants learned a nondeclarative
(implicit) visual texture discrimination
task at 9am
```
Participants groups:
• Nap (90 mins) - Used EEG to see which
participants engaged in REM sleep and
which participants did not.
• No nap
```
Participants performed the task again
at 7pm that night
49
Mednick, Nakayama, & Stickgold (2003) results
Only after a 90-minute nap that included
both slow-wave sleep and REM sleep did the
subjects’ performance improve.
50
Mednick, Nakayama, & Stickgold (2003) interpretation of results
REM sleep is important for implicit (non declarative) learning
51
Tucker et al. (2006) method
trained participants on a non declarative and declarative task
60 participants
-60 min nap- awakened before they engaged in REM sleep
6 hours later participants performance was tested
52
tucker et al (2006) results
slow wave seep improved performance on declarative task compared to no sleep participants
participants engaged in slow wave sleep did not show more engagement than no sleep participants on non declarative task
53
tucker et al (2006) interpretation of results
slow wave sleep affects declarative performance
54
sleep an dlearning
REM sleep facilitates consolidation of non declarative memories
slow wave sleep facilitates consolidation of declarative memories
55
role of slow wave sleep in navigation
participants learned their way around a virtual town
| this is a declarative form of learning
56
what do we do with information during slow wave sleep?
rehearse the information and consolidate learning
| activity of the hippocampus during learning and slow wave sound sleep
57
5 neurotransmitters that play a role in arousal (alertness and wakefulness)
```
acetylcholine
norepinephrine
serotonin
histamine
orexin
```
58
when do we have high levels of ACh
when we awake (QW, AW) or in REM sleep
59
when do we have low levels of acetylcholine?
during slow wave sleep
60
what are the hippocampus and neocortex related to?
alertness
61
what does activating ACh neurones in the basal forebrain cause?
wakefulness
62
what does activity of the noradrenergic locus coeruleus neurons increase?
vigilance
63
when does activity of noradrenergic locus coeruleus neurons increas ?
during wakefulness
64
when is activity of noradrenergic locus
| coeruleus neurons low?
during slow wave sleep
65
when is activity of noradrenergic locus
| coeruleus neurons almost 0?
during REM sleep
66
what is moment to moment activity of noradrenergic LC neurons related to?
performance on tasks requiring vigilance
67
where are most serotonergic neurons found?
in the raphe nuclei
68
what does stimulation of the raphe nuclei cause?
cortical arousal
69
what happens if you block teh synthesis of serotonin?
arousal is reduced
70
activity of serotonergic neurons during stages of sleep
most active during waking
steadily decline to almost 0 activity by REM sleep
temporarily become very active after REM sleep
71
where are histaminergic neurons located?
in the hypothalamus
72
when is activity of histaminergic neurons high?
during waking
73
when is activity of histaminergic neurons low?
during slow wave and REM sleep
74
what is teh effect of drugs that prevent the synthesis of histamine or block histamine receptors?
decrease waking
| increase sleep
75
where are cell bodies that secrete orexin?
in the lateral hypothalamus
76
what is the effect of orexin?
it has an excitatory effect in the cerebral cortex and all other regions involved in arousal and wakefulness
77
activation of orexinergic neurons
awakens mice form REM and non REM sleep
78
when do orexinergic neurons fire fastest?
in active walking
| particularly when exploring
79
when do orexinergic neurons fire less frequently?
during quiet walking and sleep
80
what 3 factors is sleep controlled by?
homeostatic
allostatic
circadian
81
primary homeostatic factor
presence or absence of adenosine
neuromodulator
released by active neurons, builds up while we are awake
destroyed by slow wave sleep
82
what is allosteric control mediated by?
hormonal and neural responses to stressful situations
83
what is necessary for sleep?
inhibition of the arousal system
84
what are sleep promoting neurons?
group of GABAnergic neurons (preoptic neuron ) in the ventrolateral preoptic area of the hypothalamus
85
what is the action of sleep promoting neurons?
to supress activity of arousal neurons
86
flip flop on: we are awake
when sleep promoting neurons in the vIPOA are inhibited and the arousal neurons are active
87
flip flop off: we are asleep
when teh sleep-promoting neurons in the vIPOA are activates and the arousal neurons are inhibited
88
what to neurons involved in sleep cannot be active at the same time?
sleep promoting neurons and arousal neurons
89
vIPOA
ventrolateral preoptic area
90
what do orexinergic neurons help stabalise?
the sleep/waking flip/flop
91
what activates orexinergic neurons
motivation to remain awake or events that disturb sleep
92
what factors control the activity of orexinergic signals?
inhibitory:
input to vlPOA because of build up of adenosine
satiety related signals
excitatory: hunger related signals
other: biological clock
93
where are REM on neurons located?
in the pons
94
where are REM off neurons located?
in the midbrain- VlPAG
95
waking: REM off
REM off region receives excitatory input from orexinergic neurons and this activation tips teh REM flip-flop into the off state
96
REM sleep- REM on
orexinergic input to REM OFF starts to decrease
The REM flip-flop tips to the on state, REM sleep begins
97
Paralysis during REM
specific neurons control the muscular paralysis during REM sleep
when REM flip-flop tips to the ON state, motor neurons in the spinal cord become inhibited, and cannot respond to signals arising from the motor cortex in their dream
98
what are the effects of damage to the 'paralysis neurons'
no inhibition of motor neurons
| person acts out their dream
99
DSM-V criteria for insomnia
difficulty getting to sleep, staying asleep or having non-restorative sleep
together with associated impairment of daytime functioning
defined in relation to a particular persons relationship w sleep
100
how many people are affected by insomnia?
9% of the population
| 1/3 report at least one nocturnal symptom
101
causes of insomnia
age: more common when older
stress
environmental factors
-electronic devices, noise and light
detrimental
-white noise or other repetitive noise
beneficial
physiology: heightened activity in the reticular activating system
changes in circadian rhythms
medical conditions
102
treatment of insomnia
typically treated with drugs
can be treated with mindfulness
chronic sleep deprivation can lead to serious health problems
-obesity, diabetes, cardiovascular disease
103
sleep apnea
form of insomnia
inability to sleep and breath at the same time
leads to a build up of carbon dioxide in the blood that stimulates chemoreceptors, causing person to wake up gasping for air
104
effect of sleep apnea
disrupts sleep affecting daytime functioning
105
can sleep apnea be corrected?
if caused by obstruction can be corrected surgically or relieved by pressurised air that keeps the airway open
106
narcolepsy symptoms
sleep attack
cataplexy
sleep paralysis
hypnagogic hallucinations
107
sleep attack
overwhelming urge to sleep
108
cataplexy
muscular paralysis of REM sleep while awake
- varying degrees of muscle weakness
- can become completely paralysed while conscious
- occurs when a person feels strong emotions or by sudden physical effort
109
sleep paralysis
REM muscular paralysis just before the onset of sleep or upon waking up
110
hypnagogic hallucinations
dreaming while awake and paralysed
| can be realistic and terrifying
111
causes of narcolepsy
hereditary element
environmental factors play a role but are unknown
orexinergic neurons are attacked by the immune system, normally in childhood
112
treatments of narcolepsy
sleep attacks can be diminished with stimulants such as: methylphenidate
REM sleep phenomenon typically treated with antidepressant drugs
most common current treatments: modafanil and/or sodium oxybate
both stimulant drugs
113
REM sleep behaviour disorder
failure to exhibit paralysis during REM sleep
acting out dreams
neurodegenerative disorder with genetic component (associated with neurodegenerative conditions such as Parkinson's)
114
how is REM sleep behaviour disorder usually treated?
with clonazepam , a benzodiazepine tranquiliser
115
slow wave sleep problems
```
sleep walking (somnambulism)
night terrors (pavor nocturnus)
bedwetting (nocturnal enuresis)
```
most frequently occur in children and all have hereditary elements
116
somnambulism
disorder of arousal
| person can engage in complex behaviours
117
pavor nocturnus
anguished screams, trembling, a rapid pulse, usually no memory for what caused the terror
118
bedwetting
10% of 7 year olds
119
fatal familial insomnia
neurodegenerative condition caused by damage to the thalamus
prion disease
120
symptoms of fatal familial insomnia
Initially presents with insomnia and very vivid dreams when the person finally
manages to sleep - EEG shows disturbances and reductions in sleep spindles and K
complexes
Disappearance of slow-wave sleep and only brief periods of REM sleep
deficits in attention and memory, followed by a dreamlike, confused state
As the disease progresses it affects the autonomic nervous system (e.g. elevated
blood pressure) and coordination (ataxia)
Psychiatric complications – panic attacks, cognitive deficits, paranoia and phobias
Ultimately inability to voluntarily move or speak (akinetic mutism), coma, and death.
