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

Mindfulness-based stress reduction for chronic pain: Enhancing psychological well-being without altering attentional biases towards pain faces

INTRODUCTION

This study examines the effects of a Mindfulness-Based Stress Reduction (MBSR) program on psychological measures and attentional patterns to pain stimuli, using eye-tracking methods, in individuals with chronic pain.

METHOD

Thirty-two participants with chronic pain and no prior mindfulness experience were randomly assigned to an experimental group or a waiting list group. Both groups completed self-report measures of symptoms, well-being, and an attentional disengagement task using emotional faces as stimuli. Assessments were conducted at two points: before and after the intervention for the experimental group, with the waiting list group serving as a control.

RESULTS

Before the MBSR program, chronic pain participants exhibited significant attentional biases towards pain-related stimuli during early attentional stages. Following the program, significant improvements were observed in depression, anxiety, stress, pain acceptance, overall well-being, and life satisfaction. However, it had a limited impact on attentional patterns, with only a significant increase in gaze duration across all stimuli.

DISCUSSION

Despite the MBSR program's success in reducing symptoms associated with chronic pain, the lack of broader attentional improvements raises questions about the mechanisms responsible for psychological improvements.

SIGNIFICANCE STATEMENT

This study pioneers the use of eye-tracking to examine how MBSR influences attention in chronic back pain. While the program improved psychological well-being, it did not generally alter attentional patterns, except for an increased ability to maintain attention across stimuli. We discuss whether this attentional change could be associated with the increased acceptance observed in the MBSR program.

Attentional Processes in Pain: The Importance of Context and Attentional Alignment

The attentional bias literature has consistently failed to take context into account. We developed a novel paradigm in immersive virtual reality (VR) with pain stimuli where it would be adaptive or nonadaptive to attend to the stimuli. Participants had to indicate the location of the stimuli. Seventy participants were recruited. The VR-attention task assessed overall attentional bias (the tendency to prioritize pain compared with nonpain stimuli) and attentional alignment (the tendency to attend to pain more in adaptive than nonadaptive situations). Pain tolerance and threshold were measured using electrocutaneous stimulation and thermal pain. We conducted 2 (context: adaptive vs nonadaptive) × 2 (congruence: congruent vs incongruent) Analysis of Covariance, controlling for threat. Participants responded to pain probes more quickly in adaptive than nonadaptive contexts. There was an overall bias away from pain-related stimuli (avoidance) in reaction time to the target. There was also an interaction where avoidance was greater in nonadaptive contexts, indicative of attentional alignment. For gaze behavior, both attentional alignment and attentional bias were observed for latency to first fixation on the target, such that participants showed vigilance for pain particularly in the adaptive context. Attentional alignment was correlated with threshold and tolerance from electrocutaneous stimulation but not thermal pain. In conclusion, we found overall attentional biases indicating vigilance (latency to first fixation) and avoidance (response to target). We also found that participants evidenced a pattern of attention favoring adaptive over nonadaptive contexts (attentional alignment). It was attentional alignment, but not overall attentional bias, that predicted pain tolerance and threshold. PERSPECTIVE: The study explored attentional processes in pain through a novel paradigm designed in VR. The results found that positive attentional alignment, or the tendency to attend to pain more in adaptive contexts rather than nonadaptive contexts, predicted pain outcomes.

Attentional biases towards emotional information in chronic pain: A multilevel meta-analysis of eye-tracking studies

OBJECTIVE

This meta-analysis reviewed the existing literature on attentional biases towards emotional stimuli measured with eye-tracking methodologies in individuals with chronic pain.

METHOD

Eighteen relevant studies (n = 1331 participants) were identified through three electronic databases: PubMed, PsycInfo, and Scopus. A multilevel random-effects meta-analysis was conducted by using the standardized mean difference between gaze variables for emotional and neutral stimuli with Hedge's correction as the effect size (ES).

RESULTS

Between-group analyses revealed that healthy individuals make longer first fixation towards neutral stimuli compared to chronic pain patients. Within-group analyses showed that, compared to the healthy control group, the chronic pain group had more first fixations towards pain-related stimuli than to neutral ones and had shorter fixation duration towards anger-related stimuli than to neutral stimuli. A moderation effect of paradigm and type of stimuli was also found.

CONCLUSIONS

This is the first meta-analysis exploring attentional biases not only towards pain-related stimuli, but also towards other emotional information. Our findings revealed that chronic pain individuals tend to focus their attention firstly on pain-related information in comparison to healthy individuals. Furthermore, chronic pain individuals maintain their attention on anger-related stimuli less than on neutral ones.

Beyond the modified dot-probe task: A meta-analysis of the efficacy of alternate attention bias modification tasks across domains

Attention biases towards disease-relevant cues have been implicated in numerous disorders and health conditions, such as anxiety, cancer, drug-use disorders, and chronic pain. Attention bias modification (ABM) has shown that changing attention biases can change related emotional processes. ABM most commonly uses a modified dot-probe task, which has received increasing criticism regarding its reliability and inconsistent findings. The purpose of the present review was thus to systematically review and meta-analyse alternative tasks used in ABM research. We sought to examine whether alternative tasks significantly changed attention biases and emotional outcomes, and critically examined whether relevant sample, task and intervention characteristics moderated each of these effect sizes. Seventy-four (completer n = 15,294) study level comparisons were included in the meta-analysis. Overall, alternative ABM designs had a medium effect on changing biases (g = 0.488), and a small, but significant effect on improving clinical outcomes (g = 0.117). We found this effect to be significantly larger for studies which successfully changed biases compared to those that did not. Across all tasks, it appeared that targeting engagement biases results in the largest change to attention biases. Importantly, we found tasks incorporating gaze-contingency - encouraging engagement with non-biased stimuli - show the most promise for improving emotional outcomes.

Investigating attention toward pain-related cues in an Arabic-speaking population with and without chronic pain

There is some evidence for attentional biases in individuals with chronic pain (CP). Cultural and linguistic differences might affect the manifestation of these processes across populations. However, such attentional biases have not been explored in the Arabic-speaking population. The current study investigated these attentional biases and possible associations with resilience. Two matched groups of Arabic-speaking participants with (58) and without (58) CP were recruited from Jordan and the United Kingdom. They completed emotionally modified versions of the Posner cueing and Stroop tasks, alongside questionnaires. Significant group differences were found for the Posner task, with the CP group exhibiting disengagement revealed by the inhibition of return (IOR) effect for sensory pain-related cues compared to delayed disengagement for the other cue types. The control group showed IOR across cue types. No group differences were found on the Stroop task. The CP group had lower resilience scores than healthy controls, and resilience moderated performance on the Posner task. The study provides preliminary evidence about the attentional processes in the Arabic population; the speed of disengagement is affected in the CP group with early disengagement for sensory pain-related information compared to affect pain and neutral stimuli. Furthermore, resilience levels in the CP and control group moderated the performance on the Posner task, suggesting that it influences attentional allocation. This study can help in understanding how the phenomenon of attention bias intertwines with the cultural and linguistic factors. Future research should further explore attentional dynamics across different time points in this population and the modulatory effect of resilience.

Vigilance to Painful Laser Stimuli is Associated with Increased State Anxiety and Tense Arousal

Introduction

Pain is frequently accompanied by enhanced arousal and hypervigilance to painful sensations. Here, we describe our findings in an experimental vigilance task requiring healthy participants to indicate when randomly timed moderately painful stimuli occur in a long train of mildly painful stimuli.

Methods

During a continuous performance task with painful laser stimuli (CPTpain), 18 participants rated pain intensity, unpleasantness, and salience. We tested for a vigilance decrement over time using classical metrics including correct targets (hits), incorrectly identified non-targets (false alarms), hit reaction time, and false alarm reaction time. We measured state anxiety and tense arousal before and after the task.

Results

We found a vigilance decrement across four 12.5-minute blocks of painful laser stimuli in hits [F3,51=2.91; p=0.043; time block 1>block 4 (t=2.77; p=0.035)]. Both self-report state anxiety (tpaired,17=3.34; p=0.0039) and tense arousal (tpaired,17=3.20; p=0.0053) increased after the task. We found a vigilance decrement during our laser pain vigilance task consistent with vigilance decrements found in other stimulus modalities. Furthermore, state anxiety positively correlated with tense arousal.

Discussion

CPTpain acutely increased tense arousal and state anxiety, consistent with previous results implicating the reciprocal interaction of state anxiety and acute painful sensations and the role of pain in augmenting tense arousal. These results may indicate a psychological process which predisposes the hypervigilant to developing greater acute pain, resulting in positive feedback, greater pain and anxiety.

Neurocognitive Mechanisms Underlying Attention Bias Towards Pain: Evidence From a Drift-Diffusion Model and Event-Related Potentials

Although combining computational modeling with event-related potentials (ERPs) can precisely characterize neurocognitive processes involved in attention bias, it has yet to be applied in the context of pain. Here, a hierarchical drift-diffusion model (DDM) along with ERPs was used to characterize the neurocognitive mechanisms underlying attention bias towards pain. A spatial cueing paradigm was adopted, in which the locations of targets were either validly or invalidly predicted by spatial cues related to pain or nonpain signals. DDM-derived nondecision time was shorter for targets validly cued by pain signals than by nonpain signals, thus indicating speeded attention engagement towards pain; drift rate was slower for targets invalidly cued by pain signals than by nonpain signals, reflecting slower attention disengagement from pain. The facilitated engagement towards pain was partially mediated by the enhanced lateralization of cue-evoked N1 amplitudes, which relate to the bottom-up, stimulus-driven processes of detecting threatening signals. On the other hand, the retarded disengagement from pain was partially mediated by the enhanced target-evoked anterior N2 amplitudes, which relate to the top-down, goal-driven processes of conflict monitoring and behavior regulating. These results demonstrated that engagement and disengagement components of pain-related attention bias are governed by distinct neurocognitive mechanisms. However, it remains possible that the findings are not pain-specific, but rather, are related to threat or aversiveness in general. This deserves to be further examined by adding a control stimulus modality. PERSPECTIVE: This study characterized the neurocognitive processes involved in attention bias towards pain through combining a hierarchical DDM and ERPs. Our results revealed distinctive neurocognitive mechanisms underlying engagement and disengagement components of attention bias. Future studies are warranted to examine whether our findings are pain-specific or not.

Trait-Anxious People Take Longer to Search for Happy Faces in the Presence of Neutral and Fearful Distractors

A large body of evidence suggests that processing of affective information is typically disrupted in anxiety. It has also been hypothesized that anxious individuals are less able to evaluate contextual cues and to respond in an adaptive way to stress. In the present study, 25 participants (16 females; 9 males) scoring high (scores of 45 or above) and 26 participants (13 females; 13 males) scoring low (scores of 35 and below) on a standardized measure of trait anxiety performed an emotion search task to investigate attentional biases when the task provides an explicit emotional context. An emotional context was set in each block by asking participants to look as quickly as possible at a face expressing a specific emotion, while eye movements were being recorded. On each trial, two faces appeared, one of them expressing the target emotion and the other one expressing a distractor emotion. High trait-anxious participants showed slower response times (time to look at the instructed emotion), regardless of the affective context, compared to the control group. Additionally, we found slower responses to happy faces (positive context) in the anxious group in the presence of neutral and fearful distractors. Cognitive control may therefore be disrupted in anxiety, as anxious people take longer to process (search for) happy faces, presumably because attentional resources are drawn by neutral and fearful distractors. Those differences were not observed in a simple reaction times task, which suggests that attentional biases, and not differential processing of low-level facial features, are responsible for those differences.

What can we learn about selective attention processes in individuals with chronic pain using reaction time tasks? A systematic review and meta-analysis

ABSTRACT

Information-processing biases such as attentional, interpretation, and memory biases are believed to play a role in exacerbating and maintaining chronic pain (CP). Evidence suggests that individuals with CP show attentional bias toward pain-related information. However, the selective attentional processes that underpin this bias are not always well outlined in the literature. To improve current understanding, a systematic review was performed using a descriptive synthesis of reaction time-based studies. A random-effects meta-analysis was added to explore whether the results of previous meta-analyses would be confirmed using studies with a larger sample size. For this review, 2008 studies were screened from 4 databases, of which 34 (participant n = 3154) were included in the review and a subset of 15 (participant n = 1339) were included in the meta-analysis. Review results were summarised by producing a descriptive synthesis for all studies. Meta-analysis results indicated a mild significant attentional bias toward sensory pain-related information (k = 15, g = 0.28, 95% CI [0.16, 0.39], I2 = 43.2%, P = 0.038), and preliminary evidence of significant moderate bias towards affective pain-related information (k = 3, g = 0.48, 95% CI [0.23, 0.72], I2 = 7.1%, P = 0.341) for CP groups compared with control groups. We explored the main tasks, stimuli, and CP subtypes used to address attentional biases and related processes. However, variation across studies did not allow for a decisive conclusion about the role of stimulus, task type, or related attentional processes. In addition, a table of CP attention-related models was produced and tested for reliability. Finally, other results and recommendations are discussed.

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.

Eye movement pattern of attention bias to emotional stimuli in women with high premenstrual symptoms

BACKGROUND AND OBJECTIVES

Premenstrual Syndrome (PMS) refers to a group of symptoms linked to the menstrual cycle. Women with PMS have cognitive mode of rumination, which leads to their attention bias to emotional stimuli. This study investigated the biases for emotional information in women with high premenstrual symptoms (HPMS) compared with women with low premenstrual symptoms (LPMS).

METHODS

A total of 38 women with HPMS and 44 women with LPMS completed self-report questionnaires and a free viewing task with eye-tracking technology.

RESULTS

The questionnaire results indicate that women in the HPMS group had higher levels of rumination than those in the LPMS group. The eye-tracking results show that women in the HPMS group had an orientation bias towards negative emotional stimuli in the early cognitive process. In the late cognitive process, women in the HPMS group had accelerated attentional disengagement to positive emotional stimuli and difficult attentional disengagement to negative emotional stimuli. Further correlation analysis revealed positive relationships between the scores of initial fixation latency bias of positive pictures in premenstrual phase and the scores of symptom rumination in both groups and between the scores of initial fixation latency bias of positive pictures in premenstrual phase and the scores of brooding in HPMS group.

LIMITATIONS

This study used a retrospective questionnaire to assess the symptoms of PMS.

CONCLUSIONS

Women with HPMS had impaired attentional engagement and disengagement to emotional stimuli compared with women with LPMS, and it may be related to their cognitive mode of rumination.

Cognitive Biases in Type 2 Diabetes and Chronic Pain

The aim of the present study was to investigate the role of cognitive processing biases in Type 2 diabetes (T2D) and chronic pain, 2 conditions that are highly co-morbid. The final sample comprised 333 individuals (86 with T2D and chronic pain, 65 with chronic pain, 76 with T2D, 106 without any form of diabetes or pain). Participants completed questionnaires assessing pain and diabetes-related outcomes, as well as measures of interpretation bias, attentional bias, and attentional bias variability. In a 2 (pain status) x 2 (T2D status) x 3 (bias valence) ANOVA design, interpretation biases were found to be stronger in individuals with chronic pain than individuals without pain, although there were no differences according to T2D status. No group differences in attentional biases were found. Among individuals with T2D, greater interpretation bias was associated with better blood glucose control, but also greater fear of hypoglycemia. For individuals with chronic pain, greater interpretation bias and attentional bias variability was associated with worse pain outcomes. Whilst interpretation bias may be present in chronic pain, it also appears to indicate better glycemic control in individuals with T2D. These findings suggest a more dynamic approach to understanding cognitive bias is needed, to consider when these biases are more or less adaptive, so that they can be better harnessed to improve outcomes for individuals with T2D who experience chronic pain. PERSPECTIVE: These findings suggest that cognitive biases can be associated with psychopathology in chronic pain and in T2D, but can also potentially be adaptive in those with T2D. Diabetes management interventions may require a careful balance between promoting sufficient concern to motivate engagement in adaptive diabetes self-management, whilst also minimizing fear of hypoglycemia.

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.

Do people with acute low back pain have an attentional bias to threat-related words?

OBJECTIVES

It has been hypothesised that attentional bias to environmental threats can contribute to persistent pain. It is unclear whether people with acute low back pain (LBP) have an attentional bias to environmental threats. We investigated if attentional bias of threat related words is different in people with acute LBP and pain-free controls.

METHODS

People with acute LBP and pain-free people completed a free viewing eye tracking task. Participants were simultaneously presented with two words, a threat related word and a neutral control word. Threat related words were general threat, affective pain and sensory pain. We conducted linear mixed models to detect differences between acute LBP and pain-free participants on five eye tracking outcome measures (dwell time, first fixation, latency to first fixation, first run dwell time and number of fixations). We calculated absolute reliability, (standard error of measure), and relative reliability (intraclass correlation coefficients [ICC 2,1]) for each eye tracking outcome measures.

RESULTS

We recruited 65 people with acute LBP and 65 pain-free controls. Participants with acute LBP had a higher proportion of fixations towards the affective pain words (M=0.5009, 95% CI=0.4941, 0.5076) than the pain-free controls had (M=0.4908, 95% CI=0.4836, 0.4979), mean between group difference = -0.0101, 95% CI [-0.0198, -0.0004], p=0.0422. There was no difference between acute LBP and pain-free controls for the remaining eye tracking outcome measures (all p>0.05). The only outcome measure that had an ICC of more than 0.7 was the latency to first fixation (affective pain words ICC=0.73, general threat words ICC=0.72).

CONCLUSIONS

When compared with pain-free controls, people with acute LBP looked more often at affective pain words relative to neutral control words. This may indicate a form of engagement bias for people with acute LBP. Attentional bias was not consistent across outcome measures or word groups. Further research is needed to investigate the potential role of attentional bias in the development of persistent pain.

Clinical relevance of attentional biases in pediatric chronic pain: an eye-tracking study

ABSTRACT

Attentional biases have been posited as one of the key mechanisms underlying the development and maintenance of chronic pain and co-occurring internalizing mental health symptoms. Despite this theoretical prominence, a comprehensive understanding of the nature of biased attentional processing in chronic pain and its relationship to theorized antecedents and clinical outcomes is lacking, particularly in youth. This study used eye-tracking to assess attentional bias for painful facial expressions and its relationship to theorized antecedents of chronic pain and clinical outcomes. Youth with chronic pain (n = 125) and without chronic pain (n = 52) viewed face images of varying levels of pain expressiveness while their eye gaze was tracked and recorded. At baseline, youth completed questionnaires to assess pain characteristics, theorized antecedents (pain catastrophizing, fear of pain, and anxiety sensitivity), and clinical outcomes (pain intensity, interference, anxiety, depression, and posttraumatic stress). For youth with chronic pain, clinical outcomes were reassessed at 3 months to assess for relationships with attentional bias while controlling for baseline symptoms. In both groups, youth exhibited an attentional bias for painful facial expressions. For youth with chronic pain, attentional bias was not significantly associated with theorized antecedents or clinical outcomes at baseline or 3-month follow-up. These findings call into question the posited relationships between attentional bias and clinical outcomes. Additional studies using more comprehensive and contextual paradigms for the assessment of attentional bias are required to clarify the ways in which such biases may manifest and relate to clinical outcomes.