Sleep and Dreaming

  1. biorhythm
    inherent timing mechanism that controls various biological processes- endogenous- comes from within

    animals near poles are more affected by seasonal changes
  2. Biological Clock
    • neural system that times behavior
    • allows animals to anticipate events before they happen 
    • ex. birds head south for winter
  3. Period
    • (no not the monthly one)
    • time required to complete a cycle of activity
  4. Circannual Rhythm
    • yearly
    • ex. migratory cycles of birds
  5. Infradian Rhythm
    • less than a year
    • human menstrual cycle (there it is!)
  6. Circadian Rhythm
    • daily cycle
    • (sleep)
  7. Ultradian Rhythm
    • Less than a day
    • (eating, pooping) 
  8. Free-Running Rhythm
    • body's own rhythm when there are no external cues
    • ex. if dim lighting/can't tell whether it's night or day than you will naturally develop a sleep cycle

    • 25-27 hour cycle
    • sleep-wake cycle shifts an hour per day
  9. Zeitgeber
    • Environmental event that entrains biological rhythms
    • Ex. "time giver"
  10. Entrainment
    Determination or modification of the period of a biorhythm.
  11. Jet Lag
    fatigue and disorientatior from rapid travel through time zones due to exposure to a changed light-dark cycle
  12. Suprachiasmatic Nucleus (SCN)
    Main pacemaker of circadian rhythms located just above the optic chiasm
  13. Retinohypothalamic Pathway
    • Neural route from a subset of cone receptors in the retinal to suprachiasmatic nucleus of the hypothalmus
    • allows light to entrain the rhythmic activity of the SCN
  14. Melatonin
    • hormone secreted by the pineal gland during the dark phase of the day-night cycle
    • influences daily and seasonal biorhythms

    In winter: melatonin levels decrease, gonads shrink, testosterone levels decrease, and sexual behavior decreases.

    In summer: melatonin levels increase, gonads grow, testosterone levels increase, and sexual behavior increases.
  15. Electroencephalogram (EEG)
    Record of brain-wave activity
  16. Electromyogram (EMG)
    Record of muscle activity
  17. Electrooculogram (EOG)
    Record of eye movements 
  18. Beta Rhythm (waking state)
    Fast brain-wave activity (15-30 Hz) pattern associated with a waking EEG
  19. Alpha Rhythm (drowsy state)
    Large, extremely regular brain waves (7-11 Hz) associated with drowsiness
  20. Delta Rhythm (sleeping state)
    Slow brain-wave activity (1-3 Hz) pattern associated with deep sleep (NREM sleep)
  21. REM Sleep (dreaming state)
    Fast brain-wave pattern displayed by the neocortical EEG record during sleep
  22. Atonia
    • no tone
    • complete muscle inactivity produced by the inhibitation of motor neurons
  23. J. Allan Hobson: Activation-synthesis
    • cortex is bombarded with signals from brainstem and produces the pattern of waking EEG
    • cortex generates images, actions and emotions from personal memory stores 
    • dreams are personal but have no meaning
  24. Areas of activation during REM sleep
    • amygdala
    • visual association areas
    • motor cortex
    • brain stem
  25. Peribrachial Area
    • Cholinergic nucleus in the dorsal brainstem has a role in REM sleep behavior
    • projects to the medial pontine reticulum

    initiates REM sleep
  26. Medial Pontine Reticular Formation (MPRF)
    • nucleus in the pons participating in REM sleep
    • ex. produces the atonia of REM sleep
  27. Annttio Revonsuo: Evolutionary Hypothesis 
    • dreams are organized and biased toward threatening images
    • dreams are biologically important-lead to enhanced performance in dealing with threatening life events (adaptive function) 
  28. Microsleep
    Brief period of sleep lasting a second or so 
  29. REM Rebound
    Subjects spend more time in REM sleep in the first available sleep session 
  30. Sleep and Memory Storage
    Sleep plays a role in solidifying and organizing events in memory
  31. Reticular Activating System (RAS) Reticular Formation
    • large reticulum- mix of cell and nuclei and nerve fibers- that runs through the center of the brainstem
    • associated with sleep-wake behavior and behavioral arousal
    • Stimulation of the RAS produces a waking EEG
    • Damage to it produces a slow-wave EEG 
Card Set
Sleep and Dreaming
Lecture 14