When becoming aware of bodily sensations
When becoming aware of bodily
sensations
The impact of pain according to patients
% response
8-10
Mean (SD)
Importance
1 Enjoyment of life 84.4 8.8 (2.05)
2 Fatigue, feeling tired 84.0 8.8 (2.01)
3 Emotional well-being (feeling sad,
depressed,…)
79.6 8.6 (2.27)
4 Physical activities (walking, climbing
stairs,…)
78.1 8.4 (2.33)
5. Weakness 75.3 8.3 (2.42)
6. Staying asleep at night 74.8 8.3 (2.45)
7. Difficulty concentrating 71.3 8.0 (2.62)
8. Falling asleep at night 66.7 7.8 (2.78)
9. Relations with family, significant others 66.0 7.7 (2.75)
10. Difficulty remembering things 65.4 7.6 (30.6)
(Turk et al., 2008)
Overview
1. Attention: back to basics
2. The bottom-up control of attention
3. The top-down facilitation of pain: the case of
(hyper)vigilance
4. The top-down inhhibition of pain: distraction
5. Conclusions and implications
• What?
• Selection of information...
at the expense of other information
• Why?
• To protect the coherence of behavior
• How?
• Optimisation of current goal-directed behavior (Top-
down control)
• Facilitation of goal-relevant information
• Inhibition of goal-irrelevant information
• Interruption of attention (Bottom-up control)
1. Attention: Back to basics
(Allport, 1989)
(Allport, 1989)
Three cases in (chronic) pain
• Bottom-up selection of pain
• Pain interrupts current goal-directed behaviour
• Pain as hardwired (false) alarm signal
• Top-down facilitation of pain-related information
• A focal goal related to pain sensitizes pain-related
information
• The case of (hyper)vigilance
• Top-down inhibition of pain-related information
– Pursuit of non-pain goal inhibits pain-related information
– Distraction strategies
(Bargh, 1994; Moors & De Houwer, 2006)
Controlled?
Automatic?
•Unintentional
•Uncontrollable
•Efficient
•Unconscious
•Intentional
•Controllable
•Inefficient
•Conscious
X
2. The bottom-up control of pain
• Abrupt onset
– Noises, flashes
• Rapidly approaching
• Saillancy
• Novelty
• Pain
– Intensity, novelty,
– Threat value (?)
6 1
6 6
6
1
1 1
1 1 1
1 1
Number Numerosity Stroop (1) Value- task: Largest digit, (2) Number-task: Largest number of digits
High-intensity pain captures
attention
1500
2000
2500
3000
3500
4000
4500
Value task Number task
Control
Low pain
High pain
(Eccleston, 1995)
• Participants
• 1400 community dwelling
from aging study
• Cognitive tests
• Stroop task
• Letter-Digit-Substitution test
• Visual Verbal Learning task
• Pain
• During the past 4 weeks, how much pain did you experience?
• Results
• Effect of severe pain on Stroop task beyond effects of age,
education, gender and depressive mood
•On-the-road driving test (95km/h)
•Standard Deviation of Lateral Position
Interim conclusions
• Chronic pain interferes with cognitive functioning– Dick et al., 2010; Glass, 2008, 2009,2010; Moriarty et al., 2011
• Various cognitive tasks– Attention, memory, speed of processing, executive functioning
– Heterogeneous results due to variety in tasks
– Especially with “difficult” tasks & “Inhibition”
• Various other factors– Depression, anxiety, fatigue, medication use,…
• Ecologically valid measure
“1”
“3”
“4”
ITI = 5000 ms
ISI = 400 ms
ITI : intertrial time intervalISI : interstimulus time interval
“2”
X
X X X
X X X X
X X
17%83%
The attentional capture of novel pain
Primary task : visual
task
• Count number of « X »
Irrelevant laser pain
• 2 stimuli of same intensity
• Frequent location
• Novel location
(Legrain et al., 2009)
The attentional capture of novel pain
(Legrain et al., 2009)
Brain mechanisms
• No specific “pain matrix”
• Largely multimodal system
• Insula, ACC, MCC,
• Saliency (threat detection)
system
• Not modality-specific
• Selection foraction/defense?
• Urgency (Simon, 1967)
(Legrain et al., 2010; Moureaux et al., in press)
Summary of bottom-up control
• Bottom up control of attention• Pain intensity
• Abrupt onset
• Unpredictability
• Threat value of pain (?)
• Pain catastrophizing
• Pain related fear
• Not unique to pain
• Attention to pain is result of
• pain-related characteristics
• other environmental demands
Overview
1. Attention: back to basics
2. The bottom-up control of attention
3. The top-down facilitation of pain: the case of
(hyper)vigilance
4. The top-down inhhibition of pain: distraction
5. Conclusions and implications
3. Top-down facilitation of pain
3. Top-down facilitation of pain-related
information: the case of (hyper)vigilance
• Vigilance
– the predisposition to attend to certain classes of
events, or the readiness to select and to respond to a
certain kind of stimulus from the external or internal
environment (Macworth, 1950)
• Vigilance paradigm
– Sustained attention in order to respond to weak
external signals
• Conscious and intentional alertness to respond
to task relevant targets (APA definition)
• No prototypical vigilance paradigm in pain research
• Manipulation of goal-relevance by taskinstructions– “detect a subtle change in pain intensity or light
intensity”. Targets were predicted, unpredicted orincorrectly predicted (Miron et al., 1989)
• Intentional and conscious direction of attentiontowards pain/somatic stimuli lead to fasterdetection and a more accurate discrimination
Multiple Sensory Signal Detection
Paradigm
(Van Hulle, Van Damme, & Crombez, in prep)
Manipulation of attention
“Did you detect …?”heat tone
+ HEAT
+ TONE
+ HEAT X X
+ TONE X X
+ HEAT
+ TONE
+ HEAT
+TONE
Congruent: 2/3 - Incongruent: 1/3
0,5
0,6
0,7
0,8
0,9
1
tone heatA
ccu
rary
(d) congruent
incongruent
(Van Hulle, Van Damme, & Crombez, in prep)
Hypervigilance
– A perceptual habit of scanning
of the body for somatic sensations
(Chapman, 1978)
– Negative affectivity:
“First, High NA’s may be more likely to notice and attend to
normal body sensations and minor aches and pain.
Second, because their scanning is fraught with anxiety
and uncertainty high NAs may interpret normal symptoms
as painful or pathological” (Watson & Pennebaker, 1989,
p. 247).
Meerkat
Hypervigilance theory:
fear and anxiety (Eysenck, 1992)
• Various components dependent upon
the imminence of threat
– General hypervigilance or distractibility
– Broad attentional field and scanning
– Specific hypervigilance (attentional bias)
– Narrow attentional field and difficulty to
disengage
Hypervigilance:
What would you expext?
“Did you detect …?”heat tone
+ HEAT
+ TONE
+ HEAT X X
+ TONE X X
+ HEAT
+ TONE
+ HEAT
+TONE
Congruent: 2/3 - Incongruent: 1/3
0,5
0,6
0,7
0,8
0,9
1
tone heatA
ccu
rary
(d) congruent
incongruent
No data yet…
What is needed?
• Hypervigilance emerges in contexts with multiple
demands
– Pain (signal) is presented in competition with other types of
information
• Hypervigilance to pain (signal) requires information
within the somatosensory modality
• Hypervigilance to pain (signal) may consist of several
components
Catastrophizing about pain
• The tendency to misinterpret and exaggerate the threat
value of situations (Salkovskis &Clark, 1993)
• An exaggerated negative orientation toward actual and
anticipated pain experiences (Sullivan et al., 1995)
•(Cor)Related to
• Trait anxiety, negative affectivity
• Pain-related fear
• Pain intensity
• Disability
•Magnification: 3-items
• “I become afraid that the pain may get worse”
•Rumination: 4-items
• “I can’t seem to keep it out of my mind”
•Helplessness: 6 items
• There is nothing I can do to reduce the intensity of the
pain
(Sullivan et al., 1995; Van Damme et al. 2002; Crombez et al., 2003;
Goubert et al. 2006))
Pain Catastrophizing Scale
for adults, children, parents (PCS)
High pitch tone
Low pitch toneand what about
the PAIN?
(Crombez et al., 1998)
First generation: primary task paradgim
No differences in self-reported intensity
External threat Internal threat
Primary task paradigm
• Threat of pain amplifies attentionalinterference by low-intensity pain stimuli
• Characteristics• Competition between stimuli: +
• Somatosensory modality: +
• Attentional components: -
• Overall measure of interference
Signal (CS) CR/UCR
Pain (UCS)
Classical conditioning paradigm
• Methodological advantage
• Experimental control over stimulus characteristics
• Use of methods in experimental psychopathology
• Theoretical advantage
• Feedforward instead of feedback mechanism
Second generation: Spatial Cueing paradigm
• Spatial cueing task (Posner, 1980)
• Target stimulus (dot) left/right
• Target preceded by cue left/right
• Modification: Cue becomes CS- (“neutral”) or
CS+ (signal for pain)
• Decomposition approach of attention
• Engagement
• Difficulty to disengage
(Van Damme et al, 2004, 2006a,b)
Spatial cueing task: Classical conditioning
Validly cued Invalidly cued
1/3 Pain
++
1/3 Pain
= CS+
= CS-
Engagement: RTvalid CS+ < RTvalid neutral/CS-
Valid and neutral cueValid and threatening cue
<
= CS+
= CS-
Disengagement: RTinvalid CS+ > RTinvalid
neutral/CS-
Invalid and neutral cueInvalid and threatening cue
>
= CS+
= CS-
290
330
370
Valid Invalid valid invalid
Res
po
nse
Tim
es (
ms)
CS+ CS-
BaselineF<1
AcquisitionF=34.88
Validly
cued
Validly
cued
Invalidly
cued
Invalidly
cued
ms
Summary: spatial cueing paradigm
• Facilitated attentional engagement with CS+ in
comparison with CS-
• Difficulty to disengage from CS+ in comparison with CS-
• Especially related to threat & catastrophizing
• Automatic capture?
• Independent from the number of stimuli (efficiency)
Third Generation: Visual Search Paradigm
• Visual search task• Coloured circles
• Oriented lines
• Task: search for straight line and
decide if __ or |
• Setsize: 3, 5 and 7
• Classical Conditioning• 1 colour (CS+) linked to a pain stimulus (ratio 1/3)
• Types of trials (no contingency between CS+ and target)• Valid trial: target is presented within the CS+
• Invalid trial: CS+ is present, target is presented somewhere else
• Baseline trial: CS+ is not present(Notebaert et al., 2010, in press)
700
800
900
1000
1100
1200
1300
1400
3 5 7
Mean
RT
Setsize
valid invalid baseline
700
800
900
1000
1100
1200
1300
1400
3 5 7
Me
an
RT
Setsize
Low-anxious
valid invalid
700
800
900
1000
1100
1200
1300
1400
3 5 7
Mea
n R
T
Setsize
High-anxious
valid invalid
700
800
900
1000
1100
1200
1300
1400
3 5 7
Me
an
RT
Setsize
valid invalid baseline
700
800
900
1000
1100
1200
1300
1400
3 5 7
Mea
n R
T
Setsize
High-anxious
valid invalid baseline
700
800
900
1000
1100
1200
1300
1400
3 5 7
Mea
n R
T
Setsize
Low-anxious
valid invalid baseline
Summary: the case of (hyper)vigilance
• Facilitated engagement of attention with CS+
• Pronounced difficulty to disengage attention from
CS+• Especially when threat, trait anxiety, catastrophizing
• “Arousal” (Vogt et al., 2008)
• Action dispostion, urge to act
•There is no attentional capture by signals of pain• Threat increases “saliency” instead of “pop out”
• When CS+ is spatially predictable then scanning
Overview
1. Attention: back to basics
2. The bottom-up control of attention
3. The top-down facilitation of pain: the case of
(hyper)vigilance
4. The top-down inhhibition of pain: distraction
5. Conclusions and implications
3. Top-down facilitation of pain-related
information: the clinical case of
hypervigilance• Vigilance
– the predisposition to attend to certain classes of
events, or the readiness to select and to respond to a
certain kind of stimulus from the external or internal
environment (Macworth, 1950)
• Vigilance paradigm
– Sustained attention in order to respond to weak
external signals
• APA-definition
– Conscious and intentional alertness to respond to
task relevant targets (APA)
A key explanatory construct
• Negative affectivity/neuroticism (Watson and
Pennebaker, 1989)
– r NA - somatic complaints = 0.40
• Hypochrondriasis (Barsky & Klerman, 1983)
• Medically unexplained disorders
– Irritable bowel syndrome (Chang et al., 2000)
– Fibromyalgia (Rollman & Lautenbacher, 1993)
But is this really
hypervigilance?
What is needed?
• Hypervigilance emerges in contexts with multiple
demands
– Pain (signal) is presented in competition with other types of
information
• Hypervigilance to pain (signal) requires information
within the somatosensory modality
• Hypervigilance to pain (signal) consists of diverse
components
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
start 33 sec
0,95 mA
Single task condition & Dual task condition
0
5
10
15
20
25
Figures Stimuli
1,3
20,43
1,41
17,02
Low fearful FM
High fearful FM
Secs.
Reaction and Detection times
*p=.027
(Peters et al., Pain, 2000)
Dual task condition
Summary: the clinical case of
hypervigilance
• Patients report mulitple somatic complaints
• Patients report more attention to somatic
complaints
• Is hypervigilance cause of somatic complaints?
– Still needs to be demonstrated.
– The search continues….
– Cause: vulnerability, initiating, maintaining &
exacerbating
Overview
1. Attention: back to basics
2. The bottom-up control of attention
3. The top-down facilitation of pain: the case of
(hyper)vigilance
4. The top-down inhhibition of pain: distraction
5. Conclusions and implications
• When does distraction works?
– “Collective ennui” (Cioffi, 1991)
– “I Know distraction works although
it doesn’t” (Leventhal, 1992)
• Cognitive factors
• Load
• Attentional set
• Working memory processes
(inhibition, switching & memory
updating)
• Affective-motivational factors
5. Top-down control & pain inhibition
the case of distraction
•Control: no task
•Low capacity: respond to number on screen
•Moderate capacity: classify odd/even
•High capacity: classify odd/even + high/low
Attentional load
(Legrain et al., 2011, submitted)
• Cognitive factors
• Load
• Attentional set
• Working memory processes
(inhibition, switching & memory
updating)
• Affective-motivational factors
5. Top-down control & pain inhibition
the case of distraction
Attenional set
•Task: Localisation task (left/right)–Cue 1: localise somatic stimulus
(vibrotactile/pain)
– Cue 2: localise tone
Exp 1: Results
(Van Ryckeghem et al. in preparation)
•Task: Categorisation– Cue 1: Categorisation of tone
(high/low tone)
– Cue 2: Categorisation of the
somatic stimulus (tactile/pain)
• Cue for Left(Right) site
Attentional set
Exp 2: Results
(Van Ryckeghem et al., in preparation)
Affective-motivational value of task
• Distraction does not work for pain catastrophizers
– Hypervigilance for pain (signals)
– Probably pain features in “attentional set”, but task irrelevant
• Experiment Cold pressor pain
– Control group (attend to sensations)
– Distraction group (auditory task)
– Motivated distraction group
• Also financial reward
(Verhoeven et al., 2010)
5
6
7
8
9
10
11
12
13
14
15
Low PCS High PCS
Pa
in
Control
Distraction
Motivated distraction
5
6
7
8
9
10
11
12
13
14
15
Low PCS High PCS
Pa
in
Control
Distraction
Motivated distraction
5
6
7
8
9
10
11
12
13
14
15
Low PCS High PCS
Pa
in
Control
Distraction
Motivated distraction
5
6
7
8
9
10
11
12
13
14
15
Low PCS High PCS
Pa
in
Control
Distraction
Motivated distraction
And what about distraction in
chronic pain patients?
• Participants
– 16 patients medically
unexplained pain
– 16 matched controls
• Tasks
– Attend towards: count
number of somatic stimuli
– Attend away: count deviant
stimuli is series of
tones/visual dots
0
5
10
15
20
25
30
Healthy
Control
Patients
Attend
towards
Attend
away
VAS
*
(Snijders et al., 2010);
(Goubert et al., 2006)
• Beware of bottom-up features
• Intentionally directing attention away from pain
• Paradoxical: “pain” in attentional set
• Effortful and after-effects (Cioffi & Holloway, 1993)
• When pain is threatening, distraction less effective
• No change in threat value
• Search to reengage in “valued activities”
Conclusions and implications
• Beware of bottom-up features
• Intentionally directing attention away from pain
• Paradoxical: “pain” in attentional set
• Effortful and after-effects (Cioffi & Holloway, 1993)
• When pain is threatening, distraction less effective
• No change in threat value
• Search to reengage in “valued activities”
Conclusions and implications
Some challenges
• Not only “direction” but also “content” of attention
– Difficulty to disengage; action disposition
• Sensory focusing: “focus upon pain in an objective way.
Try to describe sensations as accurately as possible”
• “Mindfullness”, “Acceptance & Commitment therapy”
• Believe that distraction works better than sensory
focusing (Verhoeven et al., submitted)
• Better effects than distraction (Ahles & Leventhal, 1983)
• Less rebound effects after pain stimulus (Cioffi & Holloway,
1992)