Chapter 3 - Sleep Flashcards
(23 cards)
In terms of ASC what is sleep?
sleep is described as a regularly occurring ASC that typically occurs naturally and is primarily characterised by a loss of conscious awareness.
What are the 3 main methods that are used to study sleep?
- Electroencephalograph (EEG)
- Electromyograph (EMG)
- Electro-oculargraph (EOG)
What is an Electroencephalograph?
an EEG is used to detect, amplify and record the electrical activity that is spontaneously generated by the brain during sleep and dreaming.
What is an Electromyograph?
An EMG is used to detect, amplify and record the electrical activity of muscles. it general shows the strength of the electrical activity occurring in muscles, which indicates changes in muscle activity and muscle tone.
What is an Electro-oculargraph?
An EOG measures eye movements or eye positions by detecting amplifying and recording electrical activity in eye muscles that control eye movements.
What does video monitoring do?
-records external observable physiological responses throughout the sleep cycle
it observes
-the amount of tossing and turning
-changes in posture or body position
-what happens when awakening from a nightmare/terror
-responses associated with sleepwalking
it simultaneously records sound and infrared tech that the recordings can be made in conditions with little light
Define a self report
a self-report records answers to questions or rating scales on sleep related activities or problems are commonly used in the study of sleep.
what is a sleep diary?
a sleep diary is a self reported record of an individuals sleep and waking time activities, usually over a period of several weeks.
what is NREM sleep?
approximately 80% of our sleep is spent in NREM sleep. It is the time when the body recovers, repairing body tissues, removing waste products and replenishing neurotransmitters. NREM goes through 4 stages.
Describe the difference between frequency and amplitude when discussing brain waves
Frequency is used to describe the number of brain waves per minute whereas amplitude is the height of the leaks/troughs(size)
What occurs during NREM -stage 1
In this stage is where we drift in and out of true sleep
Gradually loose our awareness of ourselves and surroundings
Physiological changes indicate low bodily arousal, a decrease in heart rate, respiration, body temperature and muscle tension
Stage 1 is known for having a hyping jerk, which is our relaxed muscles suddenly jerking
What is NREM -stage 2?
Stage 2 is light sleep, and is when we are truly asleep.
Stage 2 lasts for about 10-20 minutes
Stage 2 is a unique as it has a sleep spindle causes a burst of a higher frequency brain wave activity which last for about 1 second, sleep spindles is an indicator that the person is truly asleep. It also has K-complexes which causes a burst of low-frequency and slightly higher amplitude waves, in response to arousing stimuli
What is NREM - stage 3?
Stage 3 is the start of the deepest period of sleep which lasts for 10minutes. Heart rate, blood pressure and body temperature continue to drop with respiration slow and steady. Individuals in this stage are relax and less responsive, if awoken often feel groggy and disoriented
During stage 3 there is a reduction of the brain’s electrical activity, in which delta waves make up 20-50% of brain waves
What is NREM - stage 4??
Stage 4 is very deep sleep, it is quite similar to stage 3 in response to physiological signs. In stage 4, our muscles are completely relaxed and we barely move. Delta waves are more dominate in this stage, being slower and larger than the ones in stage 3. In stage 4 it is very difficult to wake a person.
When the wake from stage 4 they tend to have a poor memory of sleep events and up to 10 minutes to orient themselves after waking
Stage 3&4 sleepwalking, sleep-talking, night terrors occur, it also is the period of when bed wetting will occur
What is REM sleep?
REM sleep is a period of rapid eye movement sleep, during which the eyeballs rapidly move beneath the closed eyelids.
The brain wave pattern is irregular, as it consists of low amplitude and relatively high frequency beta waves, like those produced in alert wakefulness. Physiological responses are increased, even though the sleeper is totally relaxed.
-paradoxical sleep the brain is active however the body is not
-most of dreaming occurs during this stage
-REM in later in the sleep cycle can last up to an hour
What are the differences in sleep patterns over different ages?
- A newborn infant sleeps for around 16 hours a day, about 8 hours is spent in REM sleep.
- Childhood sleep 9-12 hours and spend around 2-2.5 hours in REM sleep.
- Adolescence sleep 8-9 hours a night spending 2 hours in REM sleep
- During Adulthood the total sleep time is 7-8 hours a night with 2 hours of REM sleep
- In the elderly they sleep on average of 6-7 hours with one third of it spent in REM sleep. Elderly’s sleep is much lighter with increased awakenings than when younger people. At they rarely experience NREM sleep stage 3&4
Describe the sleep-wake cycle shift
The sleep-wake cycle shift affects an adolescents ability to fall asleep at the earlier times expected of them as a child.
The shift in onset of sleep is about 1 to 2 hours longer
Define sleep debt
Sleep debt is the Accumulated nightly sleep loss that is owed and needs to be made up
Define the term sleep deprivation
Sleep deprivation means going without sleep, so it is sleep loss. Which can fall under two categories
•Partial sleep deprivation involves having less than what is normally required.
•Total sleep deprivation involves not having any sleep at all.
What is a microsleep?
A microsleep is a very short period of drowsiness or sleeping that occurs while the person is apparently awake
What is a restorative theory?
Restorative theories propose that sleep provides ‘time out’ to help us recover from depleting activities during normal waking times that use the body’s physical and mental resources.
-it is an opportunity for the body to replenish energy that was depleted during the day.
-repairs damaged cells and various muscles
-releases a growth hormone
-detoxes the body of waste products
•a criticism on this theory is it would suggest that disabled people wouldn’t need to sleep as much as a physically active person would.
What is REM rebound?
REM rebound involves catching up on REM sleep immediately following a period of lost REM sleep by spending more time than usual in REM sleep when next asleep.
What is the survival theory?
The survival theories propose that sleep evolved to enhance survival by protecting an organism through making it inactive during the part of the day when it is most risky or dangerous to move about.
Once completed its survival functions, the organism spends most of its time conserving energy, hidden and protected from predators.
-a criticism to the survival theory is they don’t explain why sleep involves a loss of awareness
