Using eye movements to investigate selective attention in chronic daily headache

Abstract

Previous research has demonstrated that chronic pain is associated with biased processing of pain-related information. Most studies have examined this bias by measuring response latencies. The present study extended previous work by recording eye movement behaviour in individuals with chronic headache and in healthy controls while participants viewed a set of images (i.e., facial expressions) from 4 emotion categories (pain, angry, happy, neutral). Biases in initial orienting were assessed from the location of the initial shift in gaze, and biases in the maintenance of attention were assessed from the duration of gaze on the picture that was initially fixated, and the mean number of visits, and mean fixation duration per image category. The eye movement behaviour of the participants in the chronic headache group was characterised by a bias in initial shift of orienting to pain. There was no evidence of individuals with chronic headache visiting more often, or spending significantly more time viewing, pain images compared to other images. Both participant groups showed a significantly greater bias to maintain gaze longer on happy images, relative to pain, angry, and neutral images. Results are consistent with a pain-related bias that operates in the orienting of attention on pain-related stimuli, and suggest that chronic pain participants' attentional biases for pain-related information are evident even when other emotional stimuli are present. Pain-related information-processing biases appear to be a robust feature of chronic pain and may have an important role in the maintenance of the disorder.

Exploring Attentional Bias for Real-World, Pain-related Information in Chronic Musculoskeletal Pain Using a Novel Change Detection Paradigm

“…The present results support those obtained with the visual-probe task, suggesting biases for pain-related information are particularly prominent at stimuli presentation times associated with rumination and maintained attention. 1,2 Furthermore, it is notable that the between-group effect size in the present study (ie, d = 0.93) is similar to that reported in a recent visual-scanning task (ie, d = 0.79), 11 and also those reported in pictorial visual-probe tasks (eg, d = 0.71 9 ; d = 0.70 10 ). This indicates that attentional biases are robust features of chronic pain, and that their strength does not diminish despite increased stimuli richness and complexity or task-related cognitive requirements.…”

“…Although previous studies have found evidence of initial orienting biases in individuals with chronic pain, the flicker task differs to the paradigms adopted in these former studies in terms of task requirements and instructions. Specifically, the visualprobe task 19 required participants to locate a single dotprobe in 1 of 2 possible locations, the visual-scanning task 11 allowed participants to view 4 facial expressions freely, and the visual-search task 12 instructed participants to search for a specific facial expression embedded among 8 faces. The flicker task is the only paradigm which presents participants with complex, real-world scenes and asks them to search for an unspecified disappearing object.…”

“…Previous research exploring attentional bias has commonly used the visualprobe task with linguistic 5-8 and pictorial 9,10 stimuli. Recently, eye-tracking research has used more ecologically valid experimental paradigms, providing evidence for painrelated biases when multiple emotionally salient images (ie, facial expressions) competing for attention are presented concurrently in visual-scanning 11 and visual-search tasks. 12 A limitation of former investigations, however, is that stimuli are presented without context.…”

“…In individuals with chronic pain, visual-probe task studies have provided evidence of more pronounced pain-related bias during longer stimuli presentation times associated with maintained attention and rumination, 1,2 and eye-tracking studies have provided evidence of bias in initial orienting of attention. 11,12,19 The present study investigated the time course of attentional bias using real-world, complex scenes. To achieve this, change-scenes and distractor-scenes controlled for low-level features were presented at exposure durations associated with processes of maintained attention and initial orienting of attention, respectively.…”

Gaze behaviour when monitoring pain faces: An eye‐tracking study

“…There are two recent eye-tracking studies using pictorial stimuli, i.e., faces displaying pain and other emotions (Vervoort et al, 2013;Liossi et al, 2014). Vervoort et al (2013) report an initial bias (vigilance) towards pain faces followed by decreasing attentional engagement (avoidance) which was mediated by the level of pain catastrophizing and self-reported pain intensity.…”