Science of Sleep

Question 1

What is content of consciousness influenced by?

Answer 1

forebrain mechanisms

Question 2

What is level of consciousness controlled by?

Answer 2

ascending sys of connections from brainstem and hypothalamus

Question 3

coma occurs with . .

Answer 3

lesions of the ascending arousal system or with diffuse bihemispheric dysfunction

Question 4

wakefulness

Answer 4

awareness of self and one’s environment

Question 5

rapid eye movement (REM) sleep

Answer 5

• unconscious
• but cortex active
• dreaming (vivid, emotional, bizarre)
• paralysis
• saccadic eye movements
• autonomic fluctuations

Question 6

Saccades

Answer 6

quick, simultaneous movements of both eyes in the same direction

Question 7

Non-REM sleep

Answer 7

• unconscious with little cortical activity
• cortical synchrony
• dreams brief and less vivid
• increased parasympathetic activity
  (note: it’s difficult to wake out of deep nonREM sleep)

Question 8

two major determinants of sleep

Answer 8

1. homeostatic component
2. circadian component

Question 9

homeostatic component

Answer 9

prolonged wakefulness –> longer, deeper sleep with more stage 3 non-REM sleep

Question 10

circadian component

Answer 10

alertness varies with time of day

Question 11

ex of somnogens

Answer 11

• adenosine
• PGD2
• muramyl dipeptides
• TNFalpha

(Note: PGD2, muramyl dipeptides, and TNFalpha are increased during inflammation)

Question 12

how does caffeine work?

Answer 12

blocks adenosine (a somnogen)

Question 14

electroencephalogram measures

Answer 14

collective activity of cortical neurons