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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Exploring the role of attentional bias modification in the experience of pain
Scientific title
Exploring the effect of single session attentional bias modification on experimental pain outcomes in university students
Secondary ID [1] 284879 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pain 292315 0
Condition category
Condition code
Musculoskeletal 292654 292654 0 0
Other muscular and skeletal disorders
Anaesthesiology 292868 292868 0 0
Pain management

Study type
Description of intervention(s) / exposure
Brief attentional bias modification will be delivered in a laboratory setting. Undergraduate students will be trained to pay less attention to pain-related words (either sensory pain or affective pain) in a computer task. Participants will also complete questionnaires, a computer task to measure interpretation biases (i.e. interpreting ambiguous stimuli as pain-related), and an acute experimental pain task. There is only one experimental pain task: the cold pressor, described as follows:

Two water tanks manufactured by Thermoline Scientific Australia were used to conduct the cold pressor task. Each tank was comprised of a 20L circulating water bath chamber (model TLWB-30), immersion cooler (TIC-400) and a heat circulator (TU-3). In order to ensure participants initial arm temperature was controlled for, they were firstly asked to submerge their arm up to the elbow for 30 seconds in the warm tank, with a maintained temperature of 37degrees C ( plus or minus 0.5). Following this, they submerged the same arm up to the elbow into the tank of cold water, maintained at 5 degrees C(plus or minus 0.5). Research in the past indicates the cold pressor task produces the “Lewis Effect”, whereby pain is produced by vasodilation of the blood vessels due to warm water, quickly followed by vasoconstriction due to cold water.
Intervention code [1] 289690 0
Other interventions
Comparator / control treatment
Training attention towards pain-related words (either sensory or affective pain). As with the experimental group, control participants will also complete the same questionnaires, a computer task to measure interpretation biases (i.e. interpreting ambiguous stimuli as pain-related), and an acute experimental pain task (the cold pressor).
Control group

Primary outcome [1] 292497 0
Pain: Average pain ratings (on a visual analogue scale; VAS) observed in response to the cold pressor task
Timepoint [1] 292497 0
Immediately following completion of the acute experimental pain task
Primary outcome [2] 292498 0
Threshold: Time taken for the participant to report experiencing pain during the cold pressor task (We use a stopwatch)
Timepoint [2] 292498 0
During the cold pressor task
Primary outcome [3] 292499 0
Pain-related distress: Ratings (0-10) of Subjective Units of Distress associated with pain, rated following task
Timepoint [3] 292499 0
Immediately following the acute experimental pain task
Secondary outcome [1] 309108 0
Hesitance: The time taken to emerge arm fully in the cold pressor task (we measure time using a stopwatch)
Timepoint [1] 309108 0
During the cold pressor task
Secondary outcome [2] 309109 0
Tolerance: time that arm is left in the cold pressor task (max 4 minutes) (We use a stopwatch to measure time)
Timepoint [2] 309109 0
During the cold pressor task
Secondary outcome [3] 309377 0
Interpretation bias: The preferential categorising of ambiguous facial expressions as pain-related rather than not pain related. This will be measured using the Incidental learning task which is administered on the computer. Reaction times are the outcome.
Timepoint [3] 309377 0
Prior to and following the attentional bias modification procedure

Key inclusion criteria
Undergraduate psychology students
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Cardiac problems
Current or recent chronic pain
Current pain on a visual analogue scale of greater than 3 out of 10 (i.e. > 3/10)

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A set of random numbers (1-4) will be generated through computer software, and will be blacked out on a computer screen. Once the participant has consented to take part, their allocation will be revealed to the experimenter.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
2x2 group between subjects AN(C)OVA (sensory vs affective words; training towards vs training away from pain words).

120 participants will be recruited, to allow for a final sample of 104 participants with drop-outs accounted for. Power analyses are based on our prior studies (e.g. McGowan et al., 2009). The effect size for a difference between the ABM group and control was large. Based on this estimate, 26 participants in each group should be sufficient to detect changes at 5% significance with a power of 80%.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 8376 0
2006 - The University Of Sydney

Funding & Sponsors
Funding source category [1] 289503 0
Self funded/Unfunded
Name [1] 289503 0
Address [1] 289503 0
Country [1] 289503 0
Primary sponsor type
The University of Sydney
The University of Sydney
NSW 2006
Secondary sponsor category [1] 288184 0
Name [1] 288184 0
Address [1] 288184 0
Country [1] 288184 0

Ethics approval
Ethics application status
Ethics committee name [1] 291251 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 291251 0
Level 2, Margaret Telfer
The University of Sydney
Sydney NSW
Ethics committee country [1] 291251 0
Date submitted for ethics approval [1] 291251 0
Approval date [1] 291251 0
Ethics approval number [1] 291251 0

Brief summary
This study aims to explore the effect of pain-related attentional bias modification on the interpretation and experience of acute pain, and on psychological variables. Participants will complete the the questionnaires, then a computer based interpretation bias task, followed by the attentional bias modification. They will then then complete the interpretation bias task again, and finally the experimental pain tasks.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 49514 0
Ms Jemma Todd
Address 49514 0
School of Psychology
Brennan MacCallum Building A18
The University of Sydney
NSW 2006
Country 49514 0
Phone 49514 0
+61 2 93512560
Fax 49514 0
Email 49514 0
Contact person for public queries
Name 49515 0
Ms Jemma Todd
Address 49515 0
School of Psychology
Brennan MacCallum Building A18
The University of Sydney
NSW 2006
Country 49515 0
Phone 49515 0
+61 2 93512560
Fax 49515 0
Email 49515 0
Contact person for scientific queries
Name 49516 0
Prof Louise Sharpe
Address 49516 0
School of Psychology
Brennan MacCallum Building A18
The University of Sydney
NSW 2006
Country 49516 0
Phone 49516 0
+61 2 93514558
Fax 49516 0
Email 49516 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary