When becoming aware of bodily sensations · 2011. 3. 15. · Hypervigilance –A perceptual habit...

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)