cutaneous pt 2

Question 1

how do we perceive objects- haptic perception

Answer 1

• humans use active touch to interact with environment
  exploration of 3D objects with hands using:
  1. sensory system
  2. motor system
  3. cognitive system

Question 2

4 exploratory procedures (EPs)

Answer 2

• lateral motion
• pressure
• enclosure
• contour following
  takes 1-2 seconds

Question 3

somatosensory center-surround receptive fields

Answer 3

lateral inhibition and center-surround receptive field

• excited by neuron above it and inhibited by neuron beside it
• becomes more clear precisely where stimulus came from

Question 4

feature detectors and tuning curves

Answer 4

orientation feature detectors built from simpler detectors

- horizontal/vertical bar detectors

Question 5

complex feature detectors in S1

Answer 5

motion sensitive- respond to any motion in field
orientation sensitive- respond to motion along particular axis
direction sensitive- respond to motion in a particular direction

Question 6

3 types of physical pain

Answer 6

1. inflammatory pain: from joints
2. neuropathic pain: nerve pinched
3. nociceptive pain: pain receptors on skin activated

Question 7

sensory vs affective pain

Answer 7

sensory - intensity of pain
ex. sharp, dull, prickly
affective- unpleasentness of pain
ex. sickening, terrifying, annoying

Question 8

direct pathway model of pain

Answer 8

pain is due to nociceptor activation

signals sent directly from skin to brain

Question 9

issues with direct pathway model

Answer 9

• soldeirs often experience little to no pain despite serious injuries
• phantom limb phenomenon
• placebo vs nocebo effect
  experiencing pain does not always correlate with physical damage

Question 10

gate control model of pain

Answer 10

nociceptor –> spinal cord –> brain

additional pathways control a gate in spinal cord

Question 11

3 pathways for gate control

Answer 11

nociceptors: activate excitatory synapse to open gate
mechanoreceptors: activate inhibitory synapse to close the gate
central control: top-down cognitive input to open or close the gate

Question 12

3 top down moderators of pain perception

Answer 12

1. expectations: placebo and nocebo
2. attention: distraction and mindfullness
3. emotions: pleasant music/ images

Question 13

attention and pain

Answer 13

pain can be moderated by attention

- if youre not aware it isnt much of a problem

Question 14

mindufllness and pain

Answer 14

focused attention, open monitoring and acceptance
- not distraction
found to reduce high and low pain

Question 15

emotions and pain

Answer 15

looking at positive pictures can reduce the experience of pain
- listening to pleasant music can reduce pain

Question 16

pain areas in the brain

Answer 16

primary somatosensory
anterior cingulate
prefrontal cortex
thalamus
insula

Question 17

sensory and affective components

Answer 17

affective: anterior cingulate, insula
sensory: prefrontal cortex, somatosensory 1 and 2

Question 18

opiods and pain

Answer 18

analgesic effect

• brain has receptor sites for opiods
• naturally occuring opiods are endorphins

Question 19

nalaxone

Answer 19

similar structure to opioids

• blocks receptor sites
• treats opiod overdoses
• increases pain because receptors cannot function as they normally would

Question 20

social pain

Answer 20

we feel pain when we observe pain in others
- empathy in ACC and insula
see increased ACC activation with rejection

Question 21

physical- social pain overlap hypothesis

Answer 21

• physical and social pain share some of the same brain networks
• support: painkillers reduce hurt feelings and pain
• counter evidence: different ACC activations for physical and social pain