Mystery of Sleep
Rebecca Reh
Nina Vujovic
Neal Dach
Salvador Dali - 1937
http://surrealists.co.uk
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Rebecca
• Why do we sleep?
• What happens when we don’t get enough?
Nina
• How does the brain regulate sleep?
Neal
• What happens in the brain during sleep?
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“If sleep does not serve an absolutely vital function,
it is the greatest mistake that evolution ever made”
- Allan Rechtschaffen
My kitten Dina, Tom Twigg photography,
Wikipedia commons, Nature publishing
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How do we know an animal is asleep?
Wikipedia commons
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What is sleep?
A behavior:
Little or no movement
Reduced responsiveness
Temporary and reversible
Usually confined to certain times/settings
A brain state:
Electrical signals inside the brain change
Can be affected by certain drugs
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Why do we sleep
?
1. Protection
2. Energy Regulation
3. Recovery
4. Process Memories
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1
Protection and Predator Avoidance
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Energy Regulation
During wake your body
uses energy
Movement
Thinking
Temperature regulation
P P P
A
+
-
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2
Energy Regulation
During wake your body
uses energy
Movement
Thinking
Temperature regulation
A
+
-
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2
Energy Regulation
During sleep your body
conserves energy.
Reduction in metabolic rate
Reduction in temperature
P P P
A
+
-
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2
Energy Regulation
During sleep loss
Changes in hormones which
regulate metabolism
Increase in appetite
P P P
A
+
-
Wikipedia commons
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3
Restoration and Recovery
Cellular housekeeping
• Increased cellular growth
• Removal of cellular waste
Immune Cell
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3
Restoration and Recovery
Cellular housekeeping
• Increased cellular growth
• Removal of cellular waste
Immune Cell
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3
Restoration and Recovery
Cellular housekeeping
• Increased cellular growth
• Removal of cellular waste
Immune Cell
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3
Restoration and Recovery
Cellular housekeeping
• Increased cellular growth
• Removal of cellular waste
Immune Cell
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4
Memory Consolidation and Learning
Memory enhancement:
Recollection is improved
Protection from interference:
Memory is not confused with new,
similar information
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Memory Consolidation and Learning
?
?
?
?
?
?
?
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Memory Consolidation and Learning
Long term
memory storage
Information
Short term
memory
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Wikipedia commons
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Sleep Deprivation Health Consequences
Cognitive and performance impairment
✴ Reduced ability to judge own impairment
✴
Adverse effects on emotional state
✴ Decreased ability for social interactions
✴ Increased pain sensitivity
✴
Long term:
Increased risk of obesity (energy regulation)
Increased risk of diabetes (energy regulation)
Increased risk of heart disease (immune response)
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http://b4kersgirl.wordpress.com/2010/09/16/going-backwards/
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Drowsy Driving
Z
Z Z
Z
Z Z
http://healthysleep.med.harvard.edu/12
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Medical Residents
80 hours a week
30 hour maximum straight shift
wikipedia commons
Air Traffic Controllers
Inconsistent shifts
Short breaks between shifts
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Summary
Sleep
Sleep Loss
Predator avoidance
- Being eaten by a lion
Energy regulation
- Increased appetite
- Hormonal changes
- Risk of obesity and diabetes
Recovery from stress
- Increased pain sensitivity
- Risk of heart disease
Consolidates memories
and enhances learning
- Impaired cognition and
performance
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