Effects of higher versus lower threat contexts on pain-related attention biases: An eye-tracking study

Fear of Pain as a Predictor for Postoperative Pain Intensity among the Patients Undergoing Thoracoscopic Surgery

Background

Fear of pain (FOP) has been recognized as an influential moderator and determinant of the perception and disability of chronic pain. However, studies on FOP in postoperative acute pain are few and inconsistent.

Objective

To explore whether FOP is related to pain intensity after thoracic surgery and provide a reference for FOP study in postoperative pain.

Methods

From February to March 2022, 89 patients completed Chinese Version of Fear of Pain-9 Items (FOP-9), Chinese version of the Brief Pain Inventory (BPI, including least, worst, and average pain) and Simplified Chinese version of the Pain Catastrophizing Scale (PCS). Correlation analyses and mediation analyses were used for exploring the relationship between factors.

Results

Mediation analyses showed that the total effects of FOP-9 on BPI all were significant (least pain: effect = 0.085, p=0.013, 95% CI = 0.019∼0.151; worst pain: effect = 0.116, p=0.004, 95% CI = 0.037∼0.196; average pain: effect = 0.102, p=0.005, 95% CI = 0.031∼0.174) indicating that FOP-9 was a predictor to BPI. The 95% bias-corrected bootstrap confidence interval of estimate of indirect effect between FOP-9 and least pain/average pain through PCS was −0.036∼0.024 and −0.003∼0.069 (all contain zero), which indicated that PCS is not a mediator between FOP-9 and least pain/average pain. However, the estimate of indirect effect between FOP-9 and worst pain through PCS were 0.048 (95% CI = 0.095∼0.088), and direct effect was not statistically significant (95% CI = −0.017∼0.153), indicating that PCS acted as a complete intermediary between FOP-9 and worst pain. FOP-9 and PCS showed significant positive prediction effect on worst pain.

Conclusions

Both trait FOP and state FOP were associated with higher postoperative pain reports after thoracic surgery. Trait FOP influences postoperative pain through the mediating effect of state FOP.

EXPRESS: Testing links between pain-related biases in visual attention and recognition memory: An eye-tracking study based on an impending pain paradigm

Although separate lines of research have evaluated pain-related biases in attention or memory, laboratory studies examining links between attention and memory for pain-related information have received little consideration. In this eye-tracking experiment, we assessed relations between pain-related attention biases (ABs) and recognition memory biases (MBs) among 122 pain-free adults randomly assigned to impending pain (n = 59) versus impending touch (n = 63) conditions wherein offsets of trials that included pain images were followed by subsequent possibly painful and non-painful somatosensory stimulation, respectively. Gaze biases of participants were assessed during presentations of pain-neutral (P-N) and happy-neutral (H-N) face image pairs within these conditions. Subsequently, condition differences in recognition accuracy for previously-viewed versus novel pained and happy face images were examined. Overall gaze durations were significantly longer for pain (versus neutral) faces that signaled impending pain than impending non-painful touch, particularly among the less resilient in the former condition. Impending pain cohorts also exhibited comparatively better recognition accuracy for both pained and happy face images. Finally, longer gaze durations on pain faces that signaled potential pain, but not potential touch, were related to more accurate recognition of previously-viewed pain faces. In sum, pain cues that signal potential personal discomfort maintain visual attention more fully and are subsequently recognized more accuracy than are pain cues that signal non-painful touch stimulation.

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 effects of attentional and interpretation biases on later pain outcomes among younger and older adults: A prospective study

BACKGROUND

Studies examining the effect of biased cognitions on later pain outcomes have primarily focused on attentional biases, leaving the role of interpretation biases largely unexplored. Also, few studies have examined pain-related cognitive biases in elderly persons. The current study aims to fill these research gaps.

METHODS

Younger and older adults with and without chronic pain (N = 126) completed an interpretation bias task and a free-viewing task of injury and neutral scenes at baseline. Participants' pain intensity and disability were assessed at baseline and at a 6-month follow-up. A machine-learning data-driven approach to analysing eye movement data was adopted.

RESULTS

Eye movement analyses revealed two common attentional pattern subgroups for scene-viewing: an "explorative" group and a "focused" group. At baseline, participants with chronic pain endorsed more injury-/illness-related interpretations compared to pain-free controls, but they did not differ in eye movements on scene images. Older adults interpreted illness-related scenarios more negatively compared to younger adults, but there was also no difference in eye movements between age groups. Moreover, negative interpretation biases were associated with baseline but not follow-up pain disability, whereas a focused gaze tendency for injury scenes was associated with follow-up but not baseline pain disability. Additionally, there was an indirect effect of interpretation biases on pain disability 6 months later through attentional bias for pain-related images.

CONCLUSIONS

The present study provided evidence for pain status and age group differences in injury-/illness-related interpretation biases. Results also revealed distinct roles of interpretation and attentional biases in pain chronicity.

SIGNIFICANCE

Adults with chronic pain endorsed more injury-/illness-related interpretations than pain-free controls. Older adults endorsed more illness interpretations than younger adults. A more negative interpretation bias indirectly predicted pain disability 6 months later through hypervigilance towards pain.

Attentional processing of pain faces and other emotional faces in chronic pain-an eye-tracking study

Altered attentional processing of pain-associated stimuli-which might take the form of either avoidance or enhanced vigilance-is thought to be implicated in the development and maintenance of chronic pain. In contrast to reaction time tasks like the dot probe, eye tracking allows for tracking the time course of visual attention and thus differentiating early and late attentional processes. Our study aimed at investigating visual attention to emotional faces in patients with chronic musculoskeletal pain (N = 20) and matched pain-free controls (N = 20). Emotional faces (pain, angry, happy) were presented in pairs with a neutral face for 2000 ms each. Three parameters were determined: First fixation probabilities, fixation durations (overall and divided in four 500 ms intervals) and a fixation bias score as the relative fixation duration of emotional faces compared to neutral faces. There were no group differences in any of the parameters. First fixation probabilities were lower for pain faces than for angry faces. Overall, we found longer fixation duration on emotional compared to neutral faces ('emotionality bias'), which is in accord with previous research. However, significant longer fixation duration compared to the neutral face was detected only for happy and angry but not for pain faces. In addition, fixation durations as well as bias scores yielded evidence for vigilant-avoidant processing of pain faces in both groups. These results suggest that attentional bias towards pain-associated stimuli might not generally differentiate between healthy individuals and chronic pain patients. Exaggerated attentional bias in patients might occur only under specific circumstances, e.g., towards stimulus material specifically relating to the specific pain of the patients under study or under high emotional distress.