intro to sleep

• What are the two components of sleep?

  Ultradian and circadian components
• Why is measuring electrical signals in the brain important for sleep research?

  It helps investigate mammals' sleep patterns
• How is electrical activity recorded from the scalp?

  As a change in voltage between electrodes
• Why is EEG recorded from the scalp?

  Because tissues conduct electrical currents from the brain
• What does EEG stand for?

  Electroencephalogram
• Why is EEG important in clinical settings?

  It measures normal and compromised brain activity
• What does an electroencephalogram measure?

  Continuous recording of brain activity
• What is the significance of placing electrodes on the face during EEG?

  To record REM and eye muscle activity
• How is sleep behaviorally defined?

  As a normal absence of consciousness
• How is sleep defined electrophysiologically?

  As a pattern of specific brain wave activity
• What happens to neuronal firing frequency during the transition from waking to nonREM sleep?

  There is a general decrease in frequency
• What determines the series of brain states during sleep?

  Activity of brainstem nuclei
• Why can't the sleep definition be readily applied to all mammals?

  Because sleep patterns vary across species
• How does prolonged sleep differ between predatory and prey species?

  Predatory species have more prolonged sleep
• What is the typical sleep duration for prey species?

  Less than 10 minutes in short bursts
• What are the characteristics of alpha waves?

  Most prominent when eyes are closed
• What do beta waves indicate?

  Being alert, attentive, and actively thinking
• Which sleep stage is associated with theta waves?

  Stage 1 and REM sleep
• What is delta activity associated with?

  Stage 3 and 4 sleep
• What characterizes slow wave sleep?

  It is a type of nREM sleep
• What is the sequence of sleep stages in a typical sleep cycle?

  First hour = nREM followed by REM
• When does stage 4 sleep typically occur?

  About an hour into the sleep cycle
• How many sleep cycles do people average per night?

  Five sleep cycles
• How does REM sleep duration change throughout the night?

  REM duration increases with each cycle
• When is deep sleep primarily present?

  Only in the first two cycles
• What physiological changes occur during REM sleep?

  Heart rate and respiration peak to waking levels
• How do rat EEG characteristics differ from humans?

  They cannot define sleep patterns similarly
• What regulates sleep homeostasis and circadian rhythms?

  Both homeostatic and circadian regulation occur
• How does the circadian system affect sleep preparation?

  It reduces core body temperature and metabolic rate
• How does aging affect hormone release and body temperature during sleep?

  Hormone release peaks later and amplitude decreases
• What system supports slow wave sleep (SWS)?

  The forebrain system independently supports SWS
• What triggers REM sleep?

  A system in the pons triggers REM sleep
• What activates the forebrain into waking?

  The brainstem activates the forebrain
• What happens when the brain is transected between the medulla and spinal cord?

  The isolated brain still generates EEG patterns
• What drives wakefulness in the CNS?

  The ascending system drives wakefulness
• What is unihemispheric sleep in ducks?

  Sleeping with one eye open and one hemisphere awake
• Why do ducks use unihemispheric sleep?

  To detect predators during sleep
• How does the risk of predators affect duck sleep patterns?

  Increased risk leads to more unihemispheric sleep
• What do frigate birds utilize unihemispheric sleep for?

  To fly long distances while sleeping
• How does wakefulness appear in EEG readings?

  Characterized by low amplitude, high frequency EEG