No evidence that attentional bias towards pain-related words is associated with verbally induced nocebo hyperalgesia: a dot-probe study

Understanding the Role of Expectancy, Anticipatory Anxiety, and Attention Bias in Nocebo Hyperalgesia: A Gaze-Contingent Attention Bias Modification Study

Nocebo effects in pain (nocebo hyperalgesia) have been thoroughly researched, and negative expectancies have been proposed as a key factor in causing nocebo hyperalgesia. However, little is known about the psychological mechanisms by which expectations exacerbate the perception of pain. A potential mechanism that has been proposed within wider pain research is pain-related attention. The aim of the present study was thus to explore whether attention bias (AB) to pain influenced nocebo hyperalgesia. One-hundred and thirty-four healthy participants were randomized in a 2 (AB training: towards vs away from pain) × 2 (nocebo condition: nocebo vs control) design. Pain-related AB was manipulated through a novel, partially gaze-contingent dot-probe task. Participants then completed either a nocebo instruction and conditioning paradigm or a matched control condition. Primary outcomes were measures of expectancy, anticipatory anxiety, and pain intensity completed during a nocebo test phase. Results showed that the AB manipulation was unsuccessful in inducing ABs either toward or away from pain. The nocebo paradigm induced significantly greater expectancy, anticipatory anxiety, and pain intensity for the nocebo groups compared to the control groups. In a posthoc analysis of participants with correctly induced ABs, AB towards pain amplified nocebo hyperalgesia, expectancy, and anticipatory anxiety relative to AB away from pain. The results are consistent with the expectancy model of nocebo effects and additionally identify anticipatory anxiety as an additional factor. Regarding AB, research is needed to develop reliable means to change attention sample-wide to corroborate the present findings. PERSPECTIVE: This article explores the role of AB, expectancy, and anticipatory anxiety in nocebo hyperalgesia. The study shows that expectancy can trigger anticipatory anxiety that exacerbates nocebo hyperalgesia. Further, successful AB training towards pain heightens nocebo hyperalgesia. These findings identify candidate psychological factors to target in minimizing nocebo hyperalgesia.

The Suicide Dot Probe Task: Psychometric properties and validity in relation to suicide-related outcomes

BACKGROUND

Attentional biases to suicide-related stimuli have been linked to suicide-related outcomes. However, behavioral tasks that have been previously modified to capture suicide-specific attentional biases have demonstrated inconsistent reliability and validity. Adaptation of the Dot Probe Task, a computerized assessment that has been adapted to study a wide variety of biases, may be a promising candidate for assessing suicide-specific biases.

METHODS

In 280 recently discharged inpatients (51% male; Mage  = 40.22 years), we evaluated the psychometric properties of a modified Suicide Dot Probe Task. Participants completed this task and assessments of suicidal thoughts and behaviors at baseline and 6-month follow-up.

RESULTS

The Suicide Dot Probe Task demonstrated poor-to-moderate internal consistency and poor test-retest reliability, and participant response times were slower to suicide-specific and dysphoric stimuli than positive stimuli. However, there were no differences based on the presence or characteristics of recent or lifetime suicidal ideation or attempts. Participants' suicide-specific biases were not predictive of suicidal ideation or attempts at follow-up.

CONCLUSIONS

The Suicide Dot Probe Task exhibited questionable reliability, and differences in attentional biases were not associated with suicidal ideation or attempts. This study contributes to a body of research demonstrating the questionable utility of several behavioral tasks to study suicide-specific attentional biases.

The relationship between expectancy, anxiety, and the nocebo effect: a systematic review and meta-analysis with recommendations for future research

Despite the theoretical prominence of expectancy and anxiety as potential mechanisms of the nocebo effect, not all studies measure expectancy and/or anxiety, and there are inconsistent findings among those that do. The present study sought to systematically review and meta-analyse available data to evaluate the relationship between expectancy, anxiety and the nocebo effect. The two key questions were: (1) whether nocebo manipulations influence expectancy and anxiety; and (2) whether expectancy and anxiety are associated with the subsequent nocebo effect. Fifty-nine independent studies (n = 3129) were identified via database searches to 1st August 2021. Nocebo manipulations reliably increased negative expectancy with a large effect (g = .837) and state anxiety with a small effect (g = .312). Changes in expectancy and state anxiety due to the nocebo manipulation were associated with larger nocebo effects (r = .376 and .234, respectively). However, there was no significant association between dispositional anxiety and the nocebo effect. These findings support theories that rely on situationally-induced expectancy and anxiety, but not dispositional anxiety, to explain nocebo effects. Importantly, being malleable, these findings suggest that interventions that target maladaptive negative expectancies and state anxiety could be beneficial for reducing the harm nocebo effects cause across health settings. Recommendations for future research are discussed.

Development and Evaluation of Linguistic Stimuli for Pain Research

Linguistic stimuli are commonly used in research to investigate the processing of pain. To provide researchers with a dataset of pain-related and non-pain-related linguistic stimuli, this research investigated 1) the associative strength between pain-related words and the pain construct; 2) the pain-relatedness ratings of pain words; and 3) the variability in the relatedness of pain words within pain word classifications (eg, sensory pain words). In Study 1, 194 pain-related and matched non-pain-related words were retrieved by reviewing the pain-related attentional bias literature. In Study 2, adults with (n = 85) and without (n = 48) self-reported chronic pain completed a speeded word categorization paradigm and rated the pain-relatedness of a subset of pain words. Analyses revealed that 1) despite differences in associative strength of 11.3% of the words between chronic and non-chronic pain groups, no overall group difference was found, 2) the chronic pain group rated the pain words as more pain-related compared to the non-chronic pain group, and 3) there was variability in the relatedness of pain words within pain word classifications. The findings highlight the importance of validating linguistic pain stimuli. The resulting dataset is openly accessible and new published sets can be added to the Linguistic Materials for Pain (LMaP) Repository. PERSPECTIVE: This article presents the development and preliminary evaluation of a large pool of pain-related and non-pain-related words in adults with and without self-reported chronic pain. Findings are discussed and guidelines are offered to select the most suitable stimuli for future research.