Altered States of Consciousness

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Altered States of Consciousness

• What is consciousness? What are the different
  states of it? What does it mean to alter it?

Salvador Dali, The Persistence of Memory, 1931
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Who sleeps?
What is sleep? A period of inactivity with
raised thresholds to arousal by external stimuli
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The Electroencephalogram (EEG)

• Measures electrical activity of groups of neurons
  across the scalp.

An event-related potential (ERP) in the temporal
lobe caused by a simple auditory stimulus
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(No Transcript)
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Slow wave sleep (SWS)
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Some characteristics of the sleep cycle

• The sleep/wake cycle is driven by a circadian
  rhythm (24 hour rhythm).
• The sleep cycle (or bout) is driven by an
  ultradian (less than 24 hour) rhythm. Your
  rest/activity activity has a 90 minute ultradian
  rhythm.
• The sleep cycle has a period of 90-120 minutes.
  This cycle may continue through wakefulness and
  may explain day dreaming.
• The sleep cycle changes with age. As we get
  older, we tend to have less REM sleep and more
  waking bouts through the cycle.

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Why sleep?

• Restoration theory
• But sleep deprivation does not interfere with
  physical capabilities and does not initiate a
  stress response
• Preservation and protection theory
• Animals that rely on vision tend to be diurnal
  (awake during daylight) and those that rely more
  on other senses, and are prey to visual animals,
  tend to be nocturnal (awake at night)
• Energy conservation

Rembrandt Sleeping Woman (1654)
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Why dream?

• Real dreaming occurs during REM (rapid eye
  movement) sleep. Stage 2 dreaming is
  characterized more as sleep thought.
• REM sleep is also called paradoxical sleep
  because the EEG pattern can look very much like
  the awake, aware EEG pattern.
• Infants spend more time in REM sleep.
• If awakened during REM sleep alertness and
  attentiveness are high. Being awakened during
  slow wave sleep (Stage 4) drowsiness and
  confusion are high.
• REM sleep deprivation causes irritability,
  problems with procedural learning (consolidation)
  and REM rebound.

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• The American Academy of Sleep Medicine (AASM)
  offers the following tips on how to get a good
  nights sleep
• Follow a consistent bedtime routine.
• Establish a relaxing setting at bedtime.
• Get a full nights sleep every night.
• Avoid foods or drinks that contain caffeine, as
  well as any medicine that has a stimulant, prior
  to bedtime.
• Do not bring your worries to bed with you.
• Do not go to bed hungry, but dont eat a big meal
  before bedtime either.
• Avoid any rigorous exercise within six hours of
  your bedtime.
• Make your bedroom quiet, dark and a little bit
  cool.
• Get up at the same time every morning.