Chapter 7 (Changes To Sleep-Wake Cycle)

Question 1

sleep deprivation

Answer 1

• not getting enough sleep for a person of your age
  partial: less than required amount of sleep with 24 hr

Question 2

causes of partial sleep deprivation

Answer 2

• lifestyles factors
• sleep apnoea
• not going into deeper NREM
• medication

Question 3

impacts of partial sleep deprivation - affective

Answer 3

• changes in emotional state and functioning
• tends to lead to quicker and more intense emotional response
  e.g: emotional outbursts, less empathy, more aggressive

Question 4

impacts of partial sleep deprivation - behavioural

Answer 4

• changes in action and way we function
  e.g: physical changes, increased risk taking, reduced motor and hand-eye coordination, eating more, experience microsleep

Question 5

impacts of partial sleep deprivation - cognitive

Answer 5

• refers to changing in thinking processes
  e.g: lapses in attention, poor decision making, impaired learning, irrational thinking, difficulty completing automatic processes

Question 6

sleep deprivation v B.A.C

Answer 6

• 17hrs wakefulness is compared to B.A.C of 0.05 - partial deprivation
• 24 hrs wakefulness is compared to B.A.C of 0.1 - full deprivation
• usually results in negative mood, increased B.A.C can either lead to positive or negative moods

Question 7

circadian rhythm sleep disorders

Answer 7

• group of sleep disorders involving a mismatch between the actual and desired sleep wake pattern
• results in less sleep

Question 8

delayed sleep phase syndrome

Answer 8

• delay in sleep onset resulting in going to sleep later and wake up later
• onset of sleep may be delayed by 2-3 hrs
• is the most common circadian rhythm
  SYMPTOMS - sleep-onset insomnia
• a person with DSPS cannot easily change their sleep pattern
• most common in adolescents (7-16%)
• result in on going partial sleep deprivation

Question 9

possible causes of DSPS in adolescents

Answer 9

internal biological: due to puberty there is a hormone induced shift of the body clock with melatonin not being released until 1-2 hrs later than childhood
internal psychological: rumination (repeatedly worrying)
external: social factors (work, study, social commitments)

Question 10

different rhythms

Answer 10

circadian rhythm - 24hr cycle
ultradian rhythm - less than 24hrs

Question 11

advanced sleep phase syndrome

Answer 11

• early sleep onset resulting in going to sleep earlier and waking up earlier
• onset of sleep may be advanced by 2-3 hrs
• most common circadian phase disorder
  SYMPTOMS - extreme tiredness in evening, early sleep onset, awakening early, tired during day, reduction in melatonin
• a person with ASPS cannot easily change their sleep pattern
• common in older people, 1% of population

Question 12

shift work

Answer 12

• involves employment outside normal 9-5 work day which disrupts natural circadian rhythm and sleep wake cycle
• people are forced to be awake when they are meant to sleep
  IMPACTS - sleepiness at work, sleep deprivation, insomnia, mood swings
  MINIMISE IMPACTS - shift friendly roster, bright light conditions, low light conditions

Question 13

bright light therapy

Answer 13

• involves exposure in intense but safe amounts of light at regular patterns to shift individuals sleep wake cycles to desired schedule
• emits strong artificial light
• exposure to bright light earlier in the day
• exposure to minimal light before bed
• opposite approach for ASPS

Question 14

sleep hygiene

Answer 14

• establish regular sleep onset and wake schedule
• minimise exposure to light before bed
• maximise light in the morning
• avoid napping
• avoid stimulants

Question 15

zeitgebers

Answer 15

• environment time cues that provide signals to the brain (SCN) to regulate the body’s circadian rhythm
• helps promote sleepiness and wakefulness at appropriate times
• light is the strongest zeitgebers
• used by SCN to adjust circadian rhythm to 24hr day

Question 16

daylight and bluelight

Answer 16

• exposure to sunlight helps ensure we are awake during the day and asleep at night
• blue light refers to light on the visible light spectrum with short waves lengths
• sun is the main source of bluelight
• is emitted through devices
• when this happens before bed the body gets conflicting information, some saying it’s time for bed while the bluelight is delaying the release of melatonin

Question 17

temperature

Answer 17

EXTERNAL - air temperature, the ideal air temp fro sleep is around 16 degrees
INTERNAL - normal body temp is 37 degrees which can vary be 1 degree throughout 24 hrs
- bodys core temp follows a 24hr circadian rhythm in line with the sun
- drop in body temp starts around 2 hrs before sleep, coinciding with melatonin release

Question 18

eating and drinking patterns

Answer 18

• sleep wake patterns can be influenced by what and when you eat and drink
• circadian rhythm prepares the body fro digestion of food during the day
  TIPS -
• maintain relatively stable eating and drinking pattern
• avoid food 3-4 hrs before bed
• avoid caffeine in the evening
• alcohol can lead to the onset of sleep but typically impairs sleep quality