1. First-Person Neuroscience of Pain:
Puzzles, Methods and Data
Simon Peter van Rysewyk
Graduate Institute of Medical Humanities,
Taipei Medical University
Brain and Consciousness Research Center,
Taipei Medical University-Shuang Ho Hospital

2. my focus today
a puzzle about introspection and the limits of
pain science
researcher-subjects
“experiential-phenomenological method”
Simon van Rysewyk 2

3. a seeming puzzle for pain science
P1 pains seem knowable via introspection
P2 introspection is subjective
P3 science is intersubjective
∴ pains cannot be a scientific object
Simon van Rysewyk 3

4. a seeming puzzle for pain science
P1 experiences seem knowable via introspection
introspection is a way of learning about one's
own ongoing, or very recently past, experiences
targets conscious experiences, beliefs, intentions
produces beliefs, judgments, knowledge
requires proximity in time
4Simon van Rysewyk

5. a seeming puzzle for pain science
P2 introspection is subjective
I have a uniquely privileged position about my
experiences that no one else can have
I can directly and immediately access my own
experiences in a way you cannot
5Simon van Rysewyk

6. a seeming puzzle for pain science
P3 science is intersubjective
no one is epistemically privileged with regard to
gathering evidence about the object of a study
6Simon van Rysewyk

7. a seeming puzzle for pain science
P1 experiences seem knowable via introspection
P2 introspection is subjective
P3 science is intersubjective
∴ experiences cannot be a scientific object
∴ experiences are non-physical
7Simon van Rysewyk

8. a seeming puzzle for pain science
P1 pains seem knowable via introspection
P2 introspection is subjective
P3 science is intersubjective
∴ pains cannot be a scientific object
∴ pains are non-physical
8Simon van Rysewyk

9. cartesian dualism
PAIN
begins in the PNS
ascends in specific
pathways
ends in a specific brain
center
introspection of pain by
the non-physical “soul”
Simon van Rysewyk 9
Rene Descartes
Treatise of man
(1662)

10. property dualism
imagine you are blind and you know all physical
facts about vision
you have neurosurgery which enables you to see
you know all physical facts about vision, but on
seeing for the first time you learn a new fact
the fact you learn is non-physical: what it is like
to see
Simon van Rysewyk 10

11. understanding the seeming puzzle
“pain cannot be a scientific object”?
false – pain science objectively studies the brain
pain dualist: does pain science study pain itself
or the brain correlates of pain?
pain depends on brain activity, but experiences
of pain are only knowable via subjective
introspection
11Simon van Rysewyk

12. understanding the seeming puzzle
∴ pain experience and brain activity are distinct
pain science studies brain correlates of pain, not
pain itself (“what it is like”)
“pain cannot be a scientific object”
12Simon van Rysewyk

13. understanding the seeming puzzle
“pain science studies brain correlates of pain,
not pain itself”
not quite right – the object of pain science is
brain activity as related to introspected pain
pain psychophysics and neuroimaging rely on
introspective report
animal studies await introspective confirmation
13Simon van Rysewyk

14. challenging property dualism
“pain science cannot know what it is like to have
a pain”
scientific explanations of experiences do not
cause the experiences to occur (e.g., to feel pain)
if I learn all physical facts about pregnancy,
would I thereby become pregnant?
14Simon van Rysewyk

15. introspection might be physical
what science knows about experience may
prove to be identical with what we know via
introspection – specific brain activity
there are not two distinct activities (cartesian
dualism)
there is only one kind of activity: brain activity
with only physical properties
Simon van Rysewyk 15

16. introspection might be physical
direct introspection is beneficial for survival
introspection accesses brain activity in a direct
way without telling us what the complex
physical properties of such brain activity are
neuroscience tells us what those physical
properties are
Simon van Rysewyk 16

17. introspection might be physical
we have color experiences without knowing
what the physical surface properties are
color neuroscience tells us what the physical
surface properties
our visual system responds to such physically
complex properties without informing us about
their properties: we simply perceive colors
Simon van Rysewyk 17

18. epistemological dualism of pain
replace cartesian dualism of pain with
epistemological dualism of pain
two forms of access to one and the same
phenomena – to the brain activity underlying
pain experiences
∴ pains are physical
Simon van Rysewyk 18

19. summary
first- and third-person access to pain is essential
in pain science and historical fact
dualism is consistent with pain science, but
epistemological dualism of pain is preferred
epistemological dualism does not entail
cartesian dualism
Simon van Rysewyk 19

20. two scientific uses of introspection
non-researcher-subject report (verbal/written)
researcher-subject report (verbal/written)
double-pain
catastrophizing and sensitization
Simon van Rysewyk 20

21. double pain
first and second pain results from a sudden
noxious stimulus to a distal part of the body
0.5 to 1.5 second delay between the two pains
impulses in thinly myelinated A axons (6–30
meters/sec) travel much faster than those in C
axons (0.5–1.5 meters/sec)
Simon van Rysewyk 21

22. double pain
Simon van Rysewyk 22

23. double pain
Lewis & Pochin 1938
independently mapped body regions wherein
they introspected double pain
double pain near the elbow but not the lower
trunk although both sites are about the same
distance from the brain
C fibers that supply the trunk have a short
conduction distance to the spinal cord
Simon van Rysewyk 23

24. Lewis & Pochin 1938
C fibers that supply the skin near the elbow have
a long conduction distance
once these C fibers enter the spinal cord, they
synapse on A neurons
differences in peripheral conduction distance
and time mean that double pain can be
discriminated at the elbow but not the trunk
Simon van Rysewyk 24

25. double pain
Landau & Bishop 1953
first pain sharp or stinging, well localized, and
brief (A fibers)
second pain diffuse, less well localized, dull,
aching, throbbing, burning (C fibers)
second pain longer lasting than first pain, vague
unpleasantness
Simon van Rysewyk 25

26. catastrophizing and sensitization
von Baeyer 2014
“When I walked on my treadmill for progressively
shorter periods of time, a powerful aversive
sensation would build up in the soles of my feet. I
would rate the pain intensity at 3/10 and the
unpleasantness at 8/10. The pain would stop a few
minutes after I stopped walking on the treadmill,
but would return quicker and stronger each time I
resumed … the problem never occurred during
ordinary walking.”
Simon van Rysewyk 26

27. von Baeyer 2014
“I told myself, ‘I wasted $1200. I'll never be able to
use this treadmill. I'll have to go back to sitting at a
desk. So much for my fitness plan,’ and similar
discouraged thoughts. When I did attempt to walk
on the treadmill while working, I could not
concentrate on the work at all: my mind was almost
fully occupied with the sensation in my feet and
with those catastrophizing thoughts. Realizing this
led to a vicious cycle of increased catastrophizing:
‘What an idiot – I ought to be able to focus on my
work!’
Simon van Rysewyk 27

28. von Baeyer 2014
von Baeyer then realized his pain was caused by
central sensitization due to repetition of
identical physical stimuli (treadmill walking):
• allodynia (feeling a normal touch as painful)
• windup (progressively stronger pain to the
exact same stimulus)
Simon van Rysewyk 28

29. von Baeyer 2014
“With this insight, the cure was obvious: I had to
vary the stimulus. When the sharp gravel
sensation starts, I kick off my shoes and
continue walking in my socks or bare feet; if I am
already barefoot when the sensitization begins, I
put my socks and shoes back on.”
changing catastrophizing can change central
sensitization: pain 1/10, unpleasantness 3/10
Simon van Rysewyk 29

30. von Baeyer 2014
“Reduction in secondary hyperalgesia was
associated with reduced pain catastrophizing,
suggesting that changes in central sensitization
are related to changes in pain-related cognitions.
Thus, we demonstrate that central sensitization
can be modified volitionally by altering pain-
related thoughts.”
Salomons et al. 2014. PAIN.
Simon van Rysewyk 30

31. researcher-subjects?
1. the results were obtained through
researchers introspecting personal pain
2. observations about specific pain experiences
3. the observations have been integrated into
our knowledge of pain
4. the observations have been replicated in
studies using standard experimental designs
and methods
Simon van Rysewyk 31

32. bias and researcher-subjects
the participation of researcher-subjects may
minimize and eliminate bias
preferable for formulating hypotheses and
designing experiments than relying on published
accounts or the imagination of others
multiple researcher-subjects likely optimal
Simon van Rysewyk 32

33. a first-person neuroscientific
method of pain
“experiential-phenomenological method”
Price DD, Aydede, M (2006) Pain: New Essays on
its Nature and the Methodology of its Study, M
Aydede (Ed.), Cambridge, Mass: MIT Press.
Simon van Rysewyk 33

34. overview
Simon van Rysewyk 34
experimental tasks phase
identify common factors
within pain experiences horizontal (first-person)
‘phenomenal structure’identify common factor
interrelationships
identify common factor-
brain relationships
vertical (third-person)
‘brain structure’

35. horizontal phase
Simon van Rysewyk 35
horizontal phase stages experimental subjects
1 question and observe
researcher-subjects
2 describe from a first-person
perspective
3 find common factors and their
interrelationships
4 use psychophysical methods to test
generality and functional
relationships between common
factors
non-researcher-subjects

36. horizontal phase
1. questioning and observing
‘What is it like to experience the unpleasantness
of laboratory pain, such as immersion of the
hand in a heated water bath?’
how of pain (sensations, thoughts, feelings)
not why pain occurs (stimulus conditions)
‘passive attention’, ‘being with pain’, immediate
retrospective attention
Simon van Rysewyk 36

37. horizontal phase
2. describing pain from the first-person
verbal/written self-reports of immediate pain:
‘My hand was immersed in a 47° C water bath
when intense burning and throbbing occurred in
my hand. Feel bothered by this and distressed.
Is it going to get stronger? Concern. Hope my
hand isn't going to be scalded’
Simon van Rysewyk 37

38. horizontal phase
3. finding common factors and interrelationships
‘phenomenological reduction’
‘Is it going to get stronger? Concern. I hope my
hand isn't going to be scalded”
can reduce to
‘I think and feel concern for future consequences
related to this pain’
Simon van Rysewyk 38

39. horizontal phase
‘Feel bothered by this and distressed’
can reduce to
‘I have a feeling of intrusion related to this pain’
Simon van Rysewyk 39

40. horizontal phase
definitional hypotheses: experiential factors
commonly present during a pain
functional hypotheses: common factor
interrelationships
Simon van Rysewyk 40

41. horizontal phase
sample definitional hypotheses:
1. an intense burning throbbing sensation in
the hand
2. an experienced intrusion or threat
associated with this sensation
3. a feeling of unpleasantness associated with
this felt intrusion or threat
Simon van Rysewyk 41

42. horizontal phase
sample functional hypotheses:
1. felt unpleasantness should increase as a
function of experienced intrusion or threat
2. experienced intrusion should increase as a
function of the intensity of burning,
throbbing sensation
Simon van Rysewyk 42

43. horizontal phase
4. applying psychophysical methods
controlled observation of ratings of experiential
factors (pain aversion) or sub-factors (concern)
rating scale methods (ratio scales)
subjects are not researchers
Simon van Rysewyk 43

44. vertical phase
correlate horizontal results with brain activity to
establish possible causal relationships
patterns of brain activity that co-vary with
different factors of pain could be identified
Simon van Rysewyk 44

45. Rainville et al. 1997
subjects rated pain sensation intensity and pain
unpleasantness of immersion of the left hand in
a 47° C water bath for 60 s
Simon van Rysewyk 45
condition hypnotic suggestion sensation
1 ↑ pain unpleasantness no
change2 ↓ pain unpleasantness

46. Rainville et al. 1997
↑ unpleasantness increased magnitudes of
pain-unpleasantness ratings and neural activity
in ACC
no change in ACC for ↓ unpleasantness
no change in S1 activity and magnitude ratings
of pain sensation intensity in both conditions
Simon van Rysewyk 46

47. Rainville et al. 1997
Simon van Rysewyk 47

48. Hofbauer et al. 2001
Simon van Rysewyk 48
subjects rated pain sensation intensity and pain
unpleasantness of immersion of the left hand in
a 47° C water bath for 60 s
condition hypnotic suggestion unpleasantness
1 ↑ sensation intensity
no change
2 ↓ sensation intensity

49. Hofbauer et al. 2001
↑ intensity increased magnitudes of pain-
intensity ratings and neural activity in S1
no change in S1 for ↓ intensity
no change in ACC activity and magnitude ratings
of pain unpleasantness in both conditions
Simon van Rysewyk 49

50. significance of pain-brain relations
changes in experience and brain activity cannot
be predicted only by stimulus properties
the neural activity sufficient for a given pain
quality of pain does not prove it exists within
one brain region
Simon van Rysewyk 50

51. future issues
less well-known introspective methods should
be used in the study of pain
relate pain and brain activity in real-time using
neurofeedback techniques
promote first-person neuroscience of pain
within pain associations (SIGs)
Simon van Rysewyk 51

52. acknowledgements
Simon van Rysewyk 52
NSC 102-2811-H-038-001
Brain and Consciousness Research Center
http://consciousbrain.tmu.edu.tw/main.php