1. Introduction

Question 1

2 umbrella theories of why we sleep

Answer 1

Homeostasis theory + cognitive theory

Question 2

Homeostasis theory of why we sleep

Answer 2

Life is energy-demanding, sleep allows to conserve energy

Question 3

Cognitive theory of why we sleep

Answer 3

Sleep is the price for brain plasticity, downscaling synaptic strength in sleep allows for more cognitive function in wake

Question 4

Do all animals sleep?

Answer 4

Yes

Question 5

Do plants sleep?

Answer 5

They have cycles, but not sure if it’s sleep yet.

Question 6

Typically, they say that there are 3 stages of consciousness. Why ones are they?

Answer 6

1. wake
2. deep sleep
3. REM sleep

Question 7

What happens during deep sleep

Answer 7

• normally no explicit awareness of self or environment
• high threshold of reactivity to external stimuli
• simple mental activity (images, thoughts, normally not a full blown dream)

Question 8

what happens in REM sleep

Answer 8

• you can have conscious experience
• low threshold of awareness of external stimuli
• both spontaneous and intentional mental activity (you can be a driver of the scenario)

Question 9

how was sleep seen historically vs now

Answer 9

historically: passive state
now: active and dynamic cyclical process

Question 10

history of sleep research: hypnotoxin theory (19th century)

Answer 10

there’s an accumulation of toxins in your blood and it needs to get out as you sleep

Question 11

what research is known to show that sleep has something to do with the blood?

Answer 11

Putting blood cells from sleep-deprived dogs into normal dogs. Normal dogs start feeling sleepy. They’re saying ok the need to sleep is in the blood.

Question 12

what did Jean Jacques d’Ortous de Mairan realize in 1729?

Answer 12

plant would continue cycle of opening and closing the leaves at the same cyclicity for some time even after before not exposed to the sun anymore. = rhythms are inbuilt