‘The Observer is the Observed: Towards Integrating Pain Phenomenology with Third-Person Scientific...

The Observer is the Observed: Towards Integrating Pain Phenomenology and

Third-Person Methods in the Scientific Study of Pain

Simon van RysewykTaiwan National Science Council Postdoctoral Fellow

Taipei Medical University

Simon van Rysewyk 2

my focus today

a puzzle for pain science about introspection

pain studies in which researcher-subjects use introspection

experiential method that integrates first and third-person methods to study pain

Simon van Rysewyk 3

a seeming puzzle for pain science

1 experiences seem knowable via introspection

2 introspection is subjective

3 science is intersubjective

∴ experiences cannot be a scientific object

(experiential science is not objective)

Simon van Rysewyk 4


like vision, pain has an object of perception (tissue damage)

unlike vision, pain itself is an experience only knowable by introspection

‘An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage’ (IASP)

Simon van Rysewyk 5


1 pain seems knowable via introspection

2 introspection is subjective

3 science is intersubjective

∴ pain cannot be a scientific object

(pain science is not objective)

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the puzzle’s impact on pain science

conclusion false – pain science studies the brain

pain experience and brain activity must be distinct (cartesian dualism)

pain science studies brain correlates of pain, not pain itself

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dualism is true of pain science

cartesian dualism implies that the subject matter of pain is brain activity related to pain

pain science is committed to introspection

pain-neuroimaging was established by robust correlation of neuroimages with pain self-report

cartesian dualism and pain science are historically consistent

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dualism is true of pain science

metaphysical dualism is not convincing

pain science can assert epistemological dualism and mind-brain identity theory

identity is advantageous: brain activity is identical to pain without revealing complex physical features of the brain

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two scientific uses of introspection

researcher-subject verbal/written reportnon-researcher-subject verbal/written report

intuitive notion of introspection:inner perception yielding knowledge of immediate personal statesintersubjectively available to researcherstaken to indicate sensory qualities

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researcher-subjects: 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)



Lewis & Pochin 1938

independently mapped body regions wherein they introspected 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


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



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



1. the results were obtained through researchers introspecting their own pain

2. observations about specific pain experiences3. the observations have been integrated into

our knowledge of pain4. the observations have been replicated in

studies using standard experimental designs and methods


relating introspection and brain activity to pain sensation and emotion

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

condition hypnotic suggestion sensation1 ↑ pain unpleasantness no

change2 ↓ pain unpleasantness



↑ unpleasantness increased magnitudes of pain-unpleasantness ratings and neural activity in ACC (area 24)

no change in ACC for ↓ unpleasantness

no change in S1 activity and magnitude ratings of pain sensation intensity in both conditions


Hofbauer et al. 2001

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 unpleasantness1 ↑ sensation intensity

no change2 ↓ sensation intensity


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


the significance of brain-pain phenomenology parallels

changes in experience and brain activity cannot be predicted only by stimulus properties

changes in experience and brain activity can be explained by analysis of experience and brain activity

the neural activity sufficient for a given pain quality of pain does not prove it exists within one brain region


an experiential approach to pain

Barrell & Barrell 1975, Price & Barrell 1980

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’


horizontal phasehorizontal phase stages experimental subjects

1 question and observe

researcher-subjects2 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


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


horizontal phase

2. describing pain from the first-personverbal/written 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’


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’


horizontal phase

‘Feel bothered by this and distressed’can reduce to‘I have a feeling of intrusion related to this pain’


horizontal phase

definitional hypotheses: experiential factors commonly present during a pain-type

functional hypotheses: common factor interrelationships


horizontal phase

sample definitional hypotheses:1. an intense burning throbbing sensation in

the hand 2. an experienced intrusion or threat associated

with this sensation3. a feeling of unpleasantness associated with

this felt intrusion or threat


horizontal phase

when the factors of intrusion or threat are present, there is a felt sense of pain

felt sense of pain is pain-aversion

pain-aversion seems about felt bodily integrity


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


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


vertical phase

correlate horizontal results with brain activity to establish possible causal relationships

patterns of cerebral cortical activity that co-vary with different factors of pain could be identified


future questions

can less well-known introspective methods be used in the study of pain?

are there experiential and neural similarities and differences between sub-types of acute and chronic pain?

can there be a ‘neural signature’ of pain?

‘The Observer is the Observed: Towards Integrating Pain Phenomenology with Third-Person Scientific...

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