1. What is sleep? Flashcards
Sleep is defined as a n____ recurring, r____ state of p____ disengagement, reduced c____ and relative i____
A naturally recurring, reversible state of perceptual disengagement, reduced consciousness and relative immobility.
The propensity of sleep is pattered by h____ and c____ factors
Homeostatic and circadian factors
Sleep is a non-____ biological state required for the ____ of life - our need for sleep parallels those for ____, ____ and ____
negotiable
maintenance
air
food
water
What are some things that sleep impacts?
1. M____, c____ and l____
2. Aspects of our e____ and how we r____ them
3. W____ clearance from the b____
4. N____ metabolism
5. I____ responses
- memory, cognition, learning
- Emotions, regulate
- Waste, brain
- Nutrient
- Immune
What is fatal familial insomnia?
A rare inherited disease that results in severe insomnia and eventually death
How long does each sleep cycle last?
Around 90 minutes
How many sleep cycles do you typically have over the course of a sleep period?
5-6 sleep cycles
What are the two broad sleep stages?
- NREM
- N1
- N2
- N3/4 - REM
- Rapid Eye Movement
When is her proportion of NREM and REM typically higher?
NREM higher at start of sleep period
REM higher towards end of sleep period
Sleep architecture is often graphically represented in a what?
Hypnogram
Where do the following attach?
1. Electroencephalogram (EEG)
2. Electromyogram (EMG)
3. Electro-oculogram (EOG)
- records electrical brain potentials from the scalp
- electrodes attached to chin to monitor muscles activity
- attached around eyes to monitor eye movements
What is on the x axis in PSG data?
Time is across x-axis
each mini square = 1 second
What is meant by frequency?
How many cycles of a waveform you see every second
What activity happens when someone is awake and attentive?
Beta activity (13-30Hz)
What activity happens when eyes are closed and starting to get drowsy?
Alpha activity (8-12Hz) - associated with state of relaxation
What do we see in N1 (transition to sleep)
Slow rolling eye ,movements
Looks like drowsiness but start to see more theta waves (4-8Hz)
What are three subtypes of hypnogogic hallucinations in stage N1?
Tetris effect
Auditory
Falling sensation
When does N2 happen?
After about 10 mins
What are K-complex delta waves in N2?
Special kind of delta wave
Sudden sharp waveforms unique to N2
Represent inhibitory mechanism to prevent awakening
How much of sleep does N2 make up?
Around 50% of total sleep
What are the two things characteristic of stage N2?
Sleep spindles
K-complexes
What other name is N3 known as?
Slow-wave sleep
What is N3 characterised by?
low frequency, high amplitude EEG activity known as delta waves
When will your body prioritise N3?
After you have been sleep deprived to compensate for the loss
How much of sleep does N3 make up?
10-20%
Decreases throughout night
What two things typically happen in stage N3?
Sleepwalking
Night terrors
Stephan et al (2021) found people perceived which stage of sleep was the deepest?
REM
What were the effects of sleeping in a rocking bed?
- Quicker to get to sleep (and quicker to get to N3 sleep)
- Increased N3 duration
- Enhanced overnight memory consolidation
What does REM sleep look like on a graph?
Similar to N1 but can see rapid eye movements and muscle tone from the chin is low
How much of sleep does REM make up?
Around 15%
What is typically most vivid in REM?
Dreaming
What name is REM sleep often called?
Paradoxical sleep (brain is very active but body can’t do anything)
REM sleep behaviour disorder is p____ in which muscle a____ is lost and a____ behaviours such as d____ e____ occur
Parasomnia in which muscle atone is lost and abnormal behaviours such as dream enactment occur
What % of people with
1. Parkinson’s disease
2. Dementia
have RBD?
- 25-58%
- 90%
Polysomnography is a procedure that uses electroe____, electro-o____ and electrom____ to assess sleep stages
a procedure that uses electroencephalogram, electro-oculogram, electromyogram to assess sleep stages
Sleep spindles are brief bursts of ____ activity (primarily during stage ____, lasting ____ seconds and named after their ____ like appearance on the EEG
brief bursts of brainwave activity (primarily during stage 2NREM, lasting 1-2 seconds and named after their spindle-like appearance of the EEG
What are sleep problems one of the earliest signs of?
Relapse of mental health disorders
Historically, sleep disturbances were considered a what of mental health disorders?
Consequence or symptom
Sleep architecture (stages and cycles) is often graphically represented in a what?
Hypnogram
Which body parts do the following record data from?
1. EEG
2. EOG
3. EMG
- Top, middle and back of head
- Eye movements
- Muscle tone (chin)
