sleep

Question 1

purpose of sleep

Answer 1

evolutionary: early humans used the day time to be productive as there was greater risk of injury or being hunted by predators in the dark. Sleeping at night also allowed for energy ti be conserved.

restorative: Homeostasis of the body is disrupted when humans are awake and sleep restores it. Sleep allows energy that declines in wake to be restored.

Question 2

sleep-wake cycle

Answer 2

the recurring pattern of wakefulness and sleep that individuals experience daily.

Question 3

circadian rhythm

Answer 3

the bodily cycle that lasts about 24 hours and controls the nocturnal release of hormones including melatonin.

Question 4

melatonin

Answer 4

the hormone that regulates the sleep-wake cycle

Question 5

stages of NREM and REM sleep

Answer 5

stage 1: NREM 1
sleep state: transitional period between sleep and wake
Heart rate: decreased
eye movement: slow rolling until sleep
muscle tension: relaxed

stage 2: NREM 2
sleep state: light non-rem sleep
heart rate: starts to slow down
eye movement: eye movement stops
muscle tension: muscles continue to relax and there are occasional twitches

stage 3: NREM 3
sleep state: deep non-rem sleep
heart rate: continues to decrease
eye movement: minimal eye movement
muscle tension: most relaxed in this stage

stage 4: REM
sleep state: dreams occur in this stage
heart rate: increases to match wake heart rate also depends on dream content
eye movement: rapid eye movement but visual info is not transmitted to brain
muscle tension: temporary paralysis (atonia) except breathing muscles and eye muscles

Question 6

causes of sleep deprivation

Answer 6

• shift work: shift work involves altering consequently reducing the quality and amount of sleep. light exposure reduces the melatonin released resulting in difficulty falling asleep.
• drugs: some drugs impact sleep stage progression. Caffeine being a stimulant increases the activity of the CNS affecting sleep. Alcohol being a depressant can disrupt sleep once worn off as it causes people to wake. People also wake up when their throat muscles relax and breathing becomes restricted.
• sleep environment: being in brightly lit environments at night reduces level of melatonin. Noise either inside or outside can cause people to wake up and decrease intensity of sleep.
• stressors: stressors can reduce sleep due to feelings of anxiety and impacts on sleep routines resulting in less sleep.

Question 7

define and explain the effects of types of sleep deprivation

Answer 7

partial/acute: the severe reduction or complete lack of sleep over a short period of time

effects: lapses in attention, irritability and decrease mood, longer reaction time, blurry vision, eye twitches and sensitivity to light.

chronic: the persistent reduction of sleep over a long period of time

effects: increased blood pressure and cholesterol resulting in heart disease, increase in energy intake resulting in obesity, insomnia, and anxiety due to poor emotion regulation.

Question 8

define sleep deprivation

Answer 8

the condition of not getting sufficient sleep

Question 9

Causes of sleep deprivation

Answer 9

• night shift can interrupt the hormones that regulate the sleep wake cycle and the circadian rhythm
• drugs such as caffeine and alcohol
• the sleep environment such as light and noise
• stressors may also affect sleep due to anxiety or disruption of sleep routine

Question 10

define sleep hygiene

Answer 10

the behaviour and sleep environment that result in healthy sleep

Question 11

techniques to improve sleep hygiene

Answer 11

• don’t look at screens for an hour before sleep because screens emit blue light disrupting the circadian rhythm. Brain stimulation occurs during use of devices increasing alertness, arousal and latency, reducing the duration and quality of sleep.
• have consistent sleep patterns as it helps to regulate the circadian rhythm. consistent sleep patterns increase the duration and amount of sleep.
• create a healthy sleeping space as circadian rhythms can change due to uncomfortable sleep space. keep room free of distractions and only use room for sleep or banging to create cognitive link between bed and sleep.

Question 12

(HE ET AL., 2020)
- AIM
- METHOD

Answer 12

aim: to determine how limiting use of mobile phones before bed affects mood, working memory, pre-sleep arousal, sleep quality and sleep habits

method
sample: 38 uni students with the habit of using phone before sleep also experiencing poor sleep quality

materials:
Positive and negative affect schedule (PANAS): a self report measure consisting of 20 statements in the form of liker scale. pos and neg emotions over past week are assessed.
N- back task: series of numbers presented on a computer and participants are to respond when a specified number is presented twice in a row and when a specified number is presented again after being presented two numbers prior.
pre sleep arousal scale (PSAS):
Pittsburgh sleep quality index (PSQI):
online sleep diary:

Question 13

(HE ET AL., 2020)
- KEY FINDINGS
- LIMITATIONS AND STRENGTHS

Answer 13

key findings: participants who did not use their mobile phone 30 mins before bed were shown to: - take less time to fall asleep, stayed asleep for longer
- had improved quality of sleep, reduced pre-sleep arousal
- reduced negative affect
- showed an improvement in working memory.
contribution: relatively new study that utilises well established measures, allowing for it to be replicated by other researchers. with replication comes the ability for assessing reliability.

limitations:
- the sample size was small, limiting the ability to generalise results to population.
- All measures, except for the n-back test, gathered subjective data from participants (self-report measures and sleep diary). subjective methods should be used in combination with physiological measures as these collect objective data that are less likely to be bias.