1. Karen Redhead & Sarah Barclay
Sleep
Karen Redhead & Sarah Barclay

2. What is Sleep... and why do we do it?
A natural and healthy, but temporary and periodical, suspension of the functions of organs of sense.

3. Why do we sleep? Theories are Sleep has a restorative function.
Why sleep at all? It seems like a big waste of time. Think of all you could be doing if you did not sleep.
Theories are
Sleep has a restorative function.
Sleep has an adaptive function.
Memory
What happens if we don’t sleep?

4. Sleep studies Electro encephalograph- EEG Look at ‘Brain waves’
Stages of sleep
- Stage 1
- Stage 2
- Stage 3
- Stage 4
- REM

5. EEG – electroencephalograph
The International placement system is used to measure the locations of electrodes
By placing electrodes in different positions it is possible to detect abnormalities in different areas of the brain
The areas that are looked at are
- Frontal – working memory, executive functioning, personality, motor function, speech production
- Temporal – Auditory processing, language comprehension, long-term memory
- Occipital – Primary visual processing
- Parietal – Sensory processing, spatial reasoning

6. Relaxed Stage Wake (eyes open)
EEG
low voltage, mixed frequency activity
Alpha waves 8-13Hz
EOG
Voluntary control of the eyes
blinks observed
Slow eye movements, rolling eyes, observed when drowsy
EMG
Relatively high voluntary movement

8. Relaxed Stage Wake (eyes closed)
EEG
rhythmic activity
prominent in the occipitals
Alpha waves, 8-13Hz
EOG
There is voluntary control of the eyes
Slow eye movements, rolling eyes, observed when drowsy
EMG
Relatively high voltage
voluntary movement

10. Stage 1 EEG EOG EMG Relatively low voltage Mixed frequency
Theta waves (3-7Hz)
<50% alpha (8-13Hz)
Vertex sharp waves
EOG
Slow eye movements
EMG
Tonic Activity
May be slightly decreased from wake

12. Stage 2 EEG EOG EMG Relatively low voltage, mixed frequency
Sleep spindles observed
K-complexes observed
EOG
Occasionally slow eye movements (observed near sleep onset)
EMG
Tonic activity
Low voltage

14. Stage 3
EEG
> 20 but < 50% high amplitude Delta waves (<2Hz)
Observed maximally in the frontal region
May observe sleep spindles and K-complexes
EOG
No eye movements
Usually picks up EEG activity
EMG
Tonic activity
Low voltage

16. Stage 4 EEG EOG EMG > 50% Delta waves, 2hz
Can observed sleep spindles
K-complexes may be present but hard to detect among high voltage waves
EOG
No eye movements
Usually pics up EEG activity
EMG
Tonic activity
Low voltage

18. REM EEG EOG EMG Relatively low voltage mixed frequency
Often resembles Stage 1
Occasional “sawtooth” waves usually in conjunction with REMs
Alpha can be present but usually 1-2 Hz slower than during wakefulness
EOG
Phasic Rapid Eye Movements
EMG
Tonic suppression
phasic twitches, usually occur with REMs

20. Activity There are 4 people one in - REM- eye movements, relaxed chin
- Stage 4- slow brain waves with big amplitude and low frequency
- Stage 2- EEG-k- complexes and spindles
- Awake- fast brain waves with low amplitude and high frequency

21. Universal Colour Hypnogram
Normal Sleep
Universal Colour Hypnogram
Yellow = Stage 1
Green = Stage 2
Teal = Stage 3
Dark Blue = Stage 4
Red = REM

22. Normal Sleep Patterns
1st cycle is approx mins, cycles then occur approx mins
As the night progresses the amount of SWS is reduced and REM sleep increased

23. Sleep Deprivation
Can be chronic- reduced sleep over a long period , or acute- no sleep last night
Affects include-aching muscles, confusion, memory lapses or loss, depression, hallucinations, hand tremors, headaches, irratability, obesity, yawning, temper tantrums in children, high blood pressure, increased stress hormones, increased risk of diabetes, symptoms similar to ADHD.

24. Sleep deprivation affects
Mood- linked to depression
Weight- linked to weight gain- obesity
Memory- impaired memory
Brain function- reduced activity in temporal lobe
Ability- driving while sleep deprived has been shown to be equivalent to driving drunk( alcohol limit)
Total sleep deprivation results in death

25. Affect of sleep deprivation on memory
Affects routine applications more than complex tasks
Tested by PVT (psychomotor vigilance task)- press a button in response to random light
In chronic sleep deprivation results are not predictable by peoples perception of impairment

26. Rebound sleep After a period of sleep deprivation
experience rebound SWS and REM sleep
Show a significant increase in slow wave sleep and REM sleep
Decrease in stage 2 sleep
Recover from sleep deprivation in a few
nights

27. REM Rebound hypnogram

28. Delayed Sleep Onset Hypnogram

29. Adolescent sleep
Experience delayed sleep phase syndrome due to the release of melatonin later this is compounded by social factors and results in:
Feel tired later and have trouble waking in the morning
Often are sleep deprived and sleep on weekends to catch up on sleep

30. Tips to try and help Stay away from caffeine and nicotine after noon.
Also avoid or limit alcohol which can disrupt sleep.
Avoid using a computer before bed.
Avoid trying to sleep with a computer or TV flickering in the room.
Avoid bright light in the evening, but open blinds or turn on lights as soon as the morning alarm goes off.
Sleep in on the weekend, but no more than 2 or 3 hours later than their usual.