1. Understanding and Managing Pain

3. Insensitivity to pain = many injuries

4. Somatosensory System
Moves info. From body to brain

5. Neurons Afferent (sensory) neurons
Interneurons - Connect sensory neurons to motor neurons
Efferent (motor) neurons

6. Somatosensory cortex

7. Brain Scans
PET
fMRI

8. Pain

9. Definition of pain
Sensation + emotional reaction to sensation

10. Types of pain Acute Chronic
Occurs when injured - cut, burn, childbirth, surgery
Adaptive
Warns of further injury
Chronic
Lasts months or years
Not adaptive
No biological benefit
Reinforced by environmental factors
Sympathy
It is still real pain

11. The experience of pain Anzio beachhead Carrying severed arm
People not realizing they were shot

12. Expression of pain Cultural background & social context
E.g. Childbirth
Rites of passage

13. Theories of pain

14. Specificity theory of pain
Pain = amount of tissue damaged
Pain largely uninfluenced by psychological forces
Problems
No specific skin receptors devoted to relaying pain
Phantom limb pain
Injury without pain
E.g. in war

15. Gate control theory of pain
Sensory input is not the only factor in pain perception
Changes in the spinal column and brain control the flow of neural impulses
Parts of spinal column can either
increase (open the gate) or
decrease (close the gate)

16. Measurement of pain 1. Self-report 2. Behavioral assessments
Rating scales (e.g. 0-10)
MMPI
2. Behavioral assessments
Observing a patient’s behavior
3. Physiological measures
Electromyography (EMG)
Muscle tension
Not a very good method (Poor validity)

17. Phantom limb pain
Common following amputation
Decreases with time

18. Managing pain with medicine
Self-paced administration of narcotics
E.g. morphine pump
Limits are programmed in
Avoids undermedication
Patients use less medication
Higher satisfaction

19. Managing pain with behavior
Relaxation training
Reduces
Headaches
Rheumatoid arthritis
Low back pain
Behavior modification
Based on operant conditioning
Positive reinforcers for pain - e.g. sympathy
Increase pain
Reinforcing desirable (non pain) behavior
Reduces pain

20. Managing pain with behavior
Cognitive behavioral therapy (CBT)
Changing your thinking patterns
E.g. “Reframing” - “Pain is weakness leaving the body” - Used in the military