EEG Patterns: Measuring Brain Activity
The Stages of Sleep: Slow Wave Sleep (SWS)
• STAGE 1: Drowsy; alpha activity; easily awakened
• STAGE 2: Sleep spindles; sound asleep, but easily
• STAGE 3: Delta Waves (20-50% of record); hard to wake up;
decrease in blood pressure, body temp, muscle tone, heart
• STAGE 4: Deep Sleep; almost continuous Delta Waves;
difficult to wake up; seldom move
The Stages of Sleep: REM Sleep
• Rapid Eye Movements
• Vivid Dreaming
• Paradoxical Sleep: Brain Wave Patterns look
alert; Theta Wave Spikes in record
• Complete loss of muscle tone
The Sleep Cycle
Theories of REM Sleep & Dreaming
• Freudian Theory (Manifest vs. Latent Content)
• Activation-Synthesis Theory (Cortex tries to make
sense of random brain activity)
• Neurocognitive Theory (Dreams are the result of
thinking under unusual circumstances)
Why Do We Sleep?
• We don’t really know, but some theories:
– Brain Development; Solidify information from the
– Repair & Restoration Theory: Restore homeostasis
to brain chemistry
– Evolutionary or Energy Conservation Theory: We
sleep to conserve energy & avoid danger
Effects of Sleep Deprivation
• No major effects up until 24 hours
• Depression, lethargy, decline on task
performance, especially vigilance tasks
• Prolonged deprivation (>120 hours) can lead
to hallucinations & psychotic behavior
• Repeated REM deprivation leads to irritability
• Metabolic processes remain largely unaffected
Sleep Disorders
Sleep Apnea
Night Terrors, Sleep Walking
Periodic Limb Movement Disorder
– (Restless Leg Syndrome)
Routes to Altered States of Consciousness
Nonchemical Environmental Pathways
Sensory Deprivation Studies
Sensory Deprivation Studies
R.E.S.T: Restricted Environmental Stimulation Technique
R.E.S.T: Restricted Environmental Stimulation Technique
Sweat Lodges
Navajo Sweat Lodge
Crow Sweat Lodge
Factors that May be Operating in Extreme or
Unusual Environments
*Intense or Novel Sensory Stimulation
*Trauma from Accidents
*Weightlessness, Pressure Changes
*Extreme Temperatures or Hypothermia
*Restricted Vision, Hearing, Smell
*Lack of Social Stimulation
*Monotonous Sensory Stimulation from Landscapes or
The Sensed Presence
A perception or feeling that another
Person is present, usually to help.
Can range from a vague feeling to
A flesh & blood entity
May be a god, spirit, ancestor,
Or person known to observer.
Why Does a Sensed Presence Appear?
• Motion of Boats
• Atmospheric/Geomagnetic Activity
• Changes in brain chemistry triggered by:
Lack of oxygen
Monotonous stimulation
Buildup of hormones
• Shifting of attention from external, ambient stimuli
to internal information we have less experience

Consciousness Powerpoint