PSY 210 pain

Question 1

definition of pain

Answer 1

an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

Question 2

multimodal means:

Answer 2

different areas of brain involved in processing pain

• physical stimulation
• emotional
• cognitive

Question 3

indicators of damage to skin

Answer 3

nociceptors in skin

Question 4

types of pain

Answer 4

inflammatory

• inflammation of joints
• tumor cells

neuropathic (damage to neurons)

• carpal tunnel syndrome (pain, numbness, and tingling in the hand and arm)
• spinal cord/ brain injury

nociceptive
- stimulation of specialized skin cells

Question 5

physical aspects of pain

Answer 5

Meyer and Campbell (‘81)

• correlation between nociceptor firing and perception of pain
• monkey nociceptors go up as temperature goes up - similar in humans
• pain was thought to only go through nociceptors (only one path)

Question 6

types of nociceptors

Answer 6

heat & cold
chemicals
severe pressure

• have different thresholds
• temp increases – damage COULD now happen; don’t feel pain every time

Question 7

pain threshold… balanced to:

Answer 7

• warn of damage

- not be affected by normal activity

Question 8

DIRECT PATHWAY MODEL OF PAIN

Answer 8

• oldest model
• nociceptors are stimulated and send signals to spinal cord – cortex
• not preferred

Question 9

problems with DIRECT PATHWAY MODEL OF PAIN

Answer 9

• pain can be affected by a person’s mental state (bad mood = more pain)
• pain can occur when there is no stimulation of the skin
• pain can be affected by a person’s attention – distracting someone
• phantom limbs (phantom pain)

Question 10

GATE THEORY

Answer 10

Melzak and Wall (‘65)
– gate = SUBSTANTIA GELATINOSA cells in dorsal horn of spinal cord

MECHANORECEPTORS/Large diameter (L-) fibers =
• gate closing
• directly to transmission cell
SG -

NOCICEPTORS/Small diameter (S-) fibers =
• gate opening
• directly to transmission cell
SG+

Question 11

where are substantia gelatinosa (SG) cells

Answer 11

dorsal horn of spinal cord

Question 12

central control

Answer 12

info from cognitive factors from the cortex stimulate SG cells

Question 13

what happens when you get novocaine at dentist

Answer 13

they shake cheek to mitigate pain by stimulating mechanoreceptors
- mixture of signals from same part of body

Question 14

gate theory… no pain versus pain

Answer 14

NO PAIN: central control/L-fibers – SG- – T-cell

PAIN: S-fibers – SG+ – T-cell

Question 15

cognitive aspects of pain perception

Answer 15

PAIN EXPECTATION
• Discloser = patient told what to expect
• Placebo effects = Real! help w/ pain management; given fake “pain meds” – expectation thins

SHIFTING ATTENTION
• Virtual reality = HOFFMAN
— people in pain used VR to chase spider and smash it
(attention diverted; experienced less pain)
• de Wied and Verbaten
— males held hand in ice water - DISTRACTED
— positive distraction: pretty girls.. chose to experience more pain
— neg distraction: took arm out faster

Question 16

Derbyshire et al

Answer 16

('04)
THREE conditions:
1- physically induced pain
2- hypnotically induced pain
3- control condition : IMAGINED PAINFUL STIMULATION

• hypnosis DID produce pain
• both physical & hypnotically pain shown in cortical areas
- direct model in pain
- multimodel/dimensional
- can produce in many ways
• hypnotic DON'T USE SKIN RECEPTORS

Question 17

Melzak and Wall

Answer 17

(‘65)

- gate theory

Question 18

Emotional aspects of pain

Answer 18

Rainville (‘97)
– Neuropsychology - using patient studies (messy)
– lesions to anterior cingulate
• no problems detecting pain (intensity; physicalness)
— same as non-lesioned people
• decreases in emotional sensation of pain (unpleasantness)

•• suggests that anterior cingulate (subcortical) is associated with emotional aspect of pain

Question 19

Rainville

Answer 19

‘97

- lesions to anterior cingulate

Question 20

Hofbauer

Answer 20

‘01
- participants presented w/ potentially painful stimuli
- rated: intensity (sensory) + unpleasantness (affective)
- using fMRI (good spatial)
1 condition: hands in hot water (STIMULUS STAYS SAME)
- HYPNOSIS: independently increase/decrease sensory and affective components ((give suggestions to patients about what will change))

RESULTS:
SUGGESTIONS ABOUT INTENSITY:
• affected intensity and unpleasantness
• S1 involved in processing intensity of pain

SUGGESTIONS ABOUT UNPLEASANTNESS:
• changed ratings of unpleasantness and anterior cingulate activiation
— important in processing emotional aspect of chain
• NO intensity/S1 activiation

•• intensity & unpleasantness can be seperated

Question 21

pain matrix

Answer 21

SUBCORTICAL
• hypothalamus
• limbic system
• thalamus
• anterior cingulate

CORTICAL
• S1 in somatosensory cortex
• insula = control processing, inhibition
• prefrontal cortices

pathway– not fully understood like others (not direct)

Question 22

artificial opioids

Answer 22

heroin
oxycodon
morphine

Question 23

what do opioids do

Answer 23

• many opiate receptor sites in brain

- stimulated (filled) – reduces pain and instills euphoria

Question 24

naturally occurring morphine

Answer 24

ENDORPHINS

- endurance in athletes.. “runner’s high”

Question 25

what does naloxone do

Answer 25

• blocks opiate sites, increasing pain

- decreased placebo effects

Question 26

narcan aka

Answer 26

naloxone

Question 27

Benedetti

Answer 27

‘99
• patients injected w/ capsaicin (chemical compound found in chilli’s that produces head/pain)
• some given topical cream to soothe
• others: placebo

RESULTS= pain perception decreased w/ placebo
– placebo effects are real