Sleep Deprivation

Question 1

Reasons for sleep deprivation

Answer 1

Shift work 
Health conditions 
Stress
Anxiety 
Stimulants 
Family commitments 
Lifestyle 
Sleep disorders

Question 2

Types of sleep deprivation

Answer 2

Total Sleep Deprivation (TSD)

Partial Sleep Deprivation (PSD)

Sleep Fragmentation

Question 3

Total Sleep Deprivation (TSD)

Answer 3

Short term being awake for < 45 hours

Long term being awake for >45 hours

Question 4

Partial Sleep Deprivation (PSD)

Answer 4

Sleep is restricted, can be acute or chronic

Question 5

Sleep Fragmentation

Answer 5

Going to sleep and waking up at the normal times but sleep is disrupted during the night meaning that more time is spent in the lighter stages of sleep rather than the deeper stages

Question 6

Signs of sleep deprivation

Answer 6

• Difficulty in making simple decisions
• Difficulty concentrating
• Falling asleep
• Still feeling hungry after eating
• Feeling more emotional than usual
• Weak immune system

Question 7

Yoo et al. (2007) participants

Answer 7

26 healthy individuals aged between 18-30

Question 8

Yoo et al. (2007) method

Answer 8

Participants assigned to either sleep deprivation group or control group

Sleep deprived group were awake for 35 hours

Participants underwent an fMRI while performing an emotional stimulus viewing task

Question 9

Yoo et al. (2007) results

Answer 9

Found that the control group and sleep deprived group showed increased activation to negative stimuli

Sleep deprived group had 60% greater activity in amygdala activity in comparison to the control

Question 10

Two key hormones in regulating hunger and appetite

Answer 10

Ghrelin

Leptin

Question 11

Ghrelin

Answer 11

Fast-acting hormone produced in cells of the stomach

Increases our drive to eat

May particularly increase the drive for unhealthy foods

Question 12

Ghrelin after sleep deprivation

Answer 12

Increase in ghrelin even after a single night of sleep deprivation

Question 13

Leptin

Answer 13

Produced in the white fat cells in the body

Suppresses appetite by communicating to the brain that the body has the energy it needs to function

Question 14

Leptin after sleep deprivation

Answer 14

Sleep deprivation suppresses leptin production making hunger more likely

Even short-term sleep deprivation can suppress leptin levels

Question 15

Sleep deprivation and the immune system

Answer 15

Same impact on the immune system as stress

Sleep deprivation reduces the number of natural killer cells in the blood stream

Hence when we are sleep deprived we may struggle to fight off a cold

Question 16

Sleep deprivation and neurodegeneration

Answer 16

A lack of sleep leads to an increase in development of a toxic protein called beta amyloid

Question 17

What is beta amyloid associated with?

Answer 17

Alzheimer’s disease

Question 18

Methodological limitations of sleep studies

Answer 18

• Don’t take into consideration naps
• Practice effects, tasks associated with cognitive function, could get better with practice
• Divergence between subjective and objective measures, not very good judge of their own sleep deprivation
• Differences in paradigms make it difficult to make comparisons, especially for partial sleep deprivation
• Individual differences

Question 19

Individual differences affecting sleep quality

Answer 19

• Age
• Gender
• Circadian rhythm
• Genetics
• Sleep homeostasis
• Health conditions
• Longer sleepers/shorter sleepers