Eye-movement behaviours when viewing real-world pain-related images

Association between attentional bias to experimentally induced pain and to pain-related words in healthy individuals: the moderating role of interpretation bias

ABSTRACT

Attentional bias to pain-related information may contribute to chronic pain maintenance. It is theoretically predicted that attentional bias to pain-related language derives from attentional bias to painful sensations; however, the complex interconnection between these types of attentional bias has not yet been tested. This study aimed to investigate the association between attentional bias to pain words and attentional bias to the location of pain, as well as the moderating role of pain-related interpretation bias in this association. Fifty-four healthy individuals performed a visual probe task with pain-related and neutral words, during which eye movements were tracked. In a subset of trials, participants were presented with a cold pain stimulus on one hand. Pain-related interpretation and memory biases were also assessed. Attentional bias to pain words and attentional bias to the pain location were not significantly correlated, although the association was significantly moderated by interpretation bias. A combination of pain-related interpretation bias and attentional bias to painful sensations was associated with avoidance of pain words. In addition, first fixation durations on pain words were longer when the pain word and cold pain stimulus were presented on the same side of the body, as compared to on opposite sides. This indicates that congruency between the locations of pain and pain-related information may strengthen attentional bias. Overall, these findings indicate that cognitive biases to pain-related information interact with cognitive biases to somatosensory information. The implications of these findings for attentional bias modification interventions are discussed.

The time course of attentional biases in pain: a meta-analysis of eye-tracking studies

ABSTRACT

Previous meta-analyses investigating attentional biases towards pain have used reaction time measures. Eye-tracking methods have been adopted to more directly and reliably assess biases, but this literature has not been synthesized in relation to pain. This meta-analysis aimed to investigate the nature and time course of attentional biases to pain-related stimuli in participants of all ages with and without chronic pain using eye-tracking studies and determine the role of task parameters and theoretically relevant moderators. After screening, 24 studies were included with a total sample of 1425 participants. Between-group analyses revealed no significant overall group differences for people with and without chronic pain on biases to pain-related stimuli. Results indicated significant attentional biases towards pain-related words or pictures across both groups on probability of first fixation (k = 21, g = 0.43, 95% confidence interval [CI] 0.15-0.71, P = 0.002), how long participants looked at each picture in the first 500 ms (500-ms epoch dwell: k = 5, g = 0.69, 95% CI 0.034-1.35, P = 0.039), and how long participants looked at each picture overall (total dwell time: k = 25, g = 0.44, 95% CI 0.15-0.72, P = 0.003). Follow-up analyses revealed significant attentional biases on probability of first fixation, latency to first fixation and dwell time for facial stimuli, and number of fixations for sensory word stimuli. Moderator analyses revealed substantial influence of task parameters and some influence of threat status and study quality. Findings support biases in both vigilance and attentional maintenance for pain-related stimuli but suggest attentional biases towards pain are ubiquitous and not related to pain status.

Attentional Bias Toward Cupping Therapy Marks: An Eye-Tracking Study

Objective

Despite the many medical benefits, cupping therapy can be difficult for some patients due to unpleasant marks on the skin. As patients are afraid of the potential painful sensation from cupping therapy, the skin reactions might produce vigilance for treatment as pain-related information. We investigated whether individuals show negative emotions and attentional bias toward pain-related residual marks from cupping therapy on the body using an eye-tracking method.

Methods

Fifty pain-free volunteers were presented with four different kinds of visual stimulation, such as the back or face region and with or without cupping marks on the skin. A cupping and a control image were presented on one screen with one image on the left side of the screen and the other on the right (locations of the images were counterbalanced across participants). The eye movements of the participants were measured while they viewed the pictures. They completed the Empathy Quotient questionnaire before the experiment and evaluated the unpleasantness level to each image during the task.

Results

Images of the back and face with cupping marks were rated significantly more unpleasant and showed a significant attentional bias (significantly longer percentage fixation time) than the control images (attentional bias score: Back + cupping: 48.1 ± 2.8%; Back: -0.7 ± 3.4%; Face + cupping: 34.5 ± 2.5%; Face: -2.2 ± 2.9%). Individuals with greater empathy exhibited significantly higher unpleasantness (r = 0.323, p < 0.05) and less attentional bias (r = -0.279, p < 0.05) to the images with cupping marks.

Conclusion

The skin reactions caused by cupping therapy evoked negative emotional responses as well as attentional bias to the reaction sites. Our findings suggest that the emotional and attentional responses to cupping therapy might reflect potential reluctance to this therapy.