Lecture 13: The Function of Sleep 1

Question 1

What was the result of the disk over water method with rats?

Answer 1

Rats deprived of sleep die within 11-32 days of ambiguous causes.

Question 2

What is the energy conservation theory? (Strong and weak form)

Answer 2

W: immobility associated with lower levels of energy expenditure than activity
S: sleep actively lowers energy expenditure below that of immobile wakefulness.

Question 3

O2 consumption _____ with sleep and time - but mostly not a _______ effect

Answer 3

falls; circadian

Question 4

What evidence is there for the energy conservation theory?

Answer 4

Men on reduced caloric days have more SWS

Question 5

List 3 criticisms of the energy conservation theory?

Answer 5

1. The fall in metabolic rate during sleep is small
2. Active heat loss during sleep onset seems counterintuitive
3. Negative correlation over species between basal metabolic rate and sleep duration in mammals

Question 6

Across species, the size of brain relative to the body is ______ related to % REM, but not to _____, and related to ____________.

Answer 6

positively; SWS; sleep cycle length

Question 7

What is the immobility hypothesis?

Answer 7

The circadian system causes rest-activity cycle. Sleep has evolved to ensure immobility during rest phase.

Question 8

What is the criticism against the immobility hypothesis.

Answer 8

Major evidence supporting hypothesis is that sleep of species appear to fit into ecological niche. Retrospective circular argument.

Question 9

Why does unihemispheric sleep exist?

Answer 9

Cetaceans would drown without coming to surface for air.