Sleep Walking & Narcolepsy Flashcards
What is narcolepsy?
Sleep disorder characterised by sudden and uncontrollable attacks of sleep at irregular and unexpected times
Who does narcolepsy affect?
1/1000 people, usually beginning in adolescence or early adulthood
What are the two main symptoms of narcolepsy?
1) Constant sleepiness
2) Cataplexy (loss of muscular control as the skeletal muscles suddenly give way)
Why might these symptoms of narcolepsy be triggered?
Emotional arousal like fear or excitement
What are some less common symptoms?
Hallucinations, sleep paralysis, disruption of sleep
What is the REM explanation for narcolepsy?
- 1960s: proposed that malfunction in system that regulates REM
- REM body is paralysed, but cataplexy may be attributed to neurons meant to be active in REM becoming active during the day
What studies have supported the REM/Narcolepsy link?
- Neuron activity in narcoleptic dogs
- Cataplexy linked to activation of cells usually only active during sleep
Has research supported this REM/N link?
No - conflicting findings, showing a need for further research
Why might non-human research into the REM/N link lack reliability/external validity?
-Differences in biology and anatomy
What is the HLA/Narcolepsy link put forth by Honda?
- Mutation of the immune system
- Increased frequency of one type of HLA in N patients
- Found on surface of WBCs and co-ordinate an immune response
Which evidence has been unsupportive of the narcolepsy and HLA link?
-High HLA reasonably common in general population too, so HLA cannot be the only explanation
Why might the HLA/N link be reductionist?
Alternative factors not taken into account
What is the final explanation for narcolepsy?
- Hypocretin plays vital role in maintaining wakefulness
- Gene defect may disrupt its production
- Shown in dogz
What have human studies found regarding the hypocretin/N link?
- Lower levels of HC in their spinal fluids
- Non inherited, but may be due to brain injury, stress, diet etc
Why does this hypocretin/N research also lend support to the HLA link?
Due to the role of HLA in immune response in cases of auto-immune attack in this area
However, what is an alternative, psychological explanation?
- Disguise sexual fantasies?!
- Conditioning in some form, exposure to yawning may cause others to feel sleepy
Why are bio-explanations more credit worthy?
- Not much research in psycho expos
- Can be tested objectively
Who does sleep walking effect?
20% of children and less than 3% of adults
What is sleep walking?
As the name suggests, walking and sometimes actions in ones sleep
Why might sleep walking have an effect on the persons life?
Could lead to injury, such as tripping
When does sleep walking occur?
NREM/SWS sleep
What if sleep walking occurs outside NREM sleep?
This is another disorder in itself
What is one explanation for sleep walking?
Incomplete arousal
How might incomplete arousal explain sleep walking?
- Mixture of delta waves and beta waves (awake brain)
- Person is awakened, but arousal is incomplete
- May be genetic
What are some alternative factors contributing to sleepwalking?
Sleep deprivation, alcohol, fever, stress, psychiatric conditions
What is some research support for the sleepwalking/sleep deprivation link?
- 40 patient observation whilst sleeping
- Behavioural checklist for behaviours such as sitting up, walking around etc
- Observed during normal nights sleep then 25 hrs without sleep
- When sleep deprived, sleep walking rose to 90% from 50
How does this research lend support to the sleep walking and sleep deprivation link?
- Dep does not lead to sleep walking in ‘normal’ people, suggesting it may only affect those with a genetic predisposition
Why might SW affect more children than adults?
Children have more SWS & system designed to inhibit motor activity in SWS is not fully matured. May be underdeveloped in adults
In support of the explanations of sleep walking, it may follow a diathesis stress model…
- Gene/environment interaction
- 1st degree relatives, 10x greater link than in gen pop
- Combined with sleep dep/fever
Positive application of sleep walking?
Expert knowledge required in case of 32 year old sleep walker who murdered his father. Claimed to have no recollection of event and was asleep at the time
The absence of such research (RWA) may have lead to..
Injustices, showing the use of psychological research in assisting in such cases
