Linda M.G. Vancleef

Optimism lowers pain: Evidence of the causal status and underlying mechanisms

Summary Optimism was causally related to lower pain intensity during a cold pressor task. Situational pain catastrophizing seemed to mediate this relationship. Abstract Previous studies have demonstrated a relation between dispositional optimism and lower pain sensitivity, but the causal status of this link remains unclear. This study sought to test the causal status by experimentally inducing a temporary optimistic state by means of writing about and visualizing a future best possible self. In addition, we explored pain expectations and (situational) pain catastrophizing as possible underlying mechanisms of the link between optimism and pain. Seventy‐nine university students participated in a cold pressor task (CPT). Before the CPT, half of them received the optimism manipulation and the other half a control manipulation. Induced optimism was related to lower pain intensity ratings during the CPT compared to the control group, thereby experimentally confirming causality. This effect was not explained by pain‐related expectations about the task. Situational pain catastrophizing, however, did seem to mediate the relation between optimism and pain. This study is novel in that it confirms the causal status of optimism towards pain. Additionally, the results reveal that positive interventions might provide a useful alternative in reducing pain catastrophizing as an extremely relevant target in pain treatment.

Do fundamental fears differentially contribute to pain-related fear and pain catastrophizing? An evaluation of the sensitivity index

Three fundamental fears—anxiety sensitivity (AS), injury/illness sensitivity (IS) and fear of negative evaluation (FNE) – have been proposed to underlie common fears and psychopathological conditions. In pain research, the relation between AS and (chronic) pain processes was the subject of several studies, whereas the possible role of IS has been ignored. The current research examines the role of IS with respect to various pain‐related variables in two studies. In the first study, 192 healthy college students completed the Sensitivity Index (SI; a composite measure assessing the three fundamental fears) and various pain‐related questionnaires. In a second study, 60 students out of the original sample took part in a pain induction procedure and completed the SI as well. We first examined the properties of the SI. Factor analysis on the SI replicated the proposed factor structure [Taylor S. The structure of fundamental fears, J Behav Ther Exp Psychiat 1993;24:289–99]. However, some items of the ASI did show problematic loadings and were therefore excluded in subsequent analyses. The main hypothesis of the current study states that IS is a stronger predictor than AS of pain catastrophizing and fear of pain as assessed by self‐report measures, and of pain tolerance and anticipatory fear of pain as assessed in a pain induction study. This hypothesis could be confirmed for all variables, except for pain tolerance, which was not predicted by any of the three fundamental fears. The current study can be considered as an impetus for devoting attention to IS in future pain research.

Increasing optimism abolishes pain-induced impairments in executive task performance

Summary Pain interferes with subsequent task performance, and optimism can potentially be used as a protective factor against this interference effect of pain on executive functioning. ABSTRACT Coping with the demands of pain diminishes self‐regulatory capacity and causes self‐regulatory fatigue, which then leads to deteriorated executive task performance. It has been suggested that optimism can counteract the depletion of self‐regulatory capacity. This study employed a 2 (optimism/no optimism) × 2 (pain/no pain) between‐subjects design to explore whether (1) experimentally induced pain (cold pressor task) deteriorates subsequent executive task performance, and (2) whether an optimism induction can counteract this sustained deteriorating effect of pain on executive task performance. Results indicated that although pain led to significantly worse performance on the executive functioning task in the no optimism condition, this sustained deteriorating effect of pain on task performance was abolished in the optimism condition. This finding is imperative because it suggests that optimism may be an important factor to implement in current psychological treatment approaches to diminish the negative impact of chronic pain on the ability to function in daily life.

Dimensional and Componential Structure of a Hierarchical Organization of Pain-Related Anxiety Constructs.

Research has identified several anxiety and fear constructs that contribute directly or indirectly to the chronic course of pain. One way to gain insight into the frequently observed interrelations between these constructs may be by conceptualizing them within a hierarchical structure. In this structure, general and specific constructs are proposed at different levels of a hierarchical tree. The present study sought to find evidence for this idea by exploring the dimensional and componential structure of a hierarchical representation of pain-related anxiety constructs. Small cards describing the individual items of 9 pain-related anxiety measures were presented to undergraduate students (N = 294), who were asked to sort them into piles of what they perceived as items of similar meaning. Cluster analysis (additive tree analyses) revealed cluster groups that could be interpreted along the lines of the proposed hierarchical structure. Multidimensional scaling analysis showed that the similarity data are characterized by a dimension that runs from general affective to pain-specific concerns. This study thus offers empirical support for the postulation of a general and specific hierarchical ordering of these constructs. Furthermore, its results endorse the independent use of various pain-related anxiety measures in research and practice aiming to assess negative emotional constructs that contribute to pain.

More optimism, less pain! The influence of generalized and pain-specific expectations on experienced cold-pressor pain

Accumulating evidence suggests that dispositional optimism might be a protective factor against experiencing pain. The current paper presents two studies investigating the association between dispositional optimism and experimental pain. Moreover, the influence of pain-specific expectations on this association is investigated. In Study 1, mediation of pain-specific expectations in the relation between dispositional optimism and pain was hypothesized. Expected and experienced pain ratings were obtained from 66 healthy participants undergoing a cold pressor tolerance task. In Study 2, the moderating effect of dispositional optimism on the association between induced pain expectations and pain reports was studied in 60 healthy participants undergoing a 1-min cold pressor task. Both studies controlled for individual differences in fear of pain. Significant associations between dispositional optimism and pain ratings were found in both studies, although the exact time point of these associations differed. Subscale analyses revealed that only the pessimism subscale contributed significantly to these findings. We found no evidence for hypothesized mediation and moderation effects. Alternative explanations for the optimism-pain association are discussed.

Interpreting ambiguous health and bodily threat : Are individual differences in pain-related vulnerability constructs associated with an on-line negative interpretation bias?

The present study examined the association between pain-related anxiety and an on-line interpretation bias for putative physical health threat. Healthy volunteers (n=80) completed measures on Anxiety Sensitivity, Injury/illness Sensitivity, Fear of Pain and Pain Catastrophizing. Furthermore, they performed an interpretation task, in which spontaneous (on-line) inferences were indirectly assessed from reaction times and accuracy of a lexical decision to the final word of an ambiguous description. Results demonstrated a general facilitation of responses to final words that endorsed a health-threatening resolution of ambiguity (e.g., illness). This effect correlated positively with individual levels of Fear of Pain, but was found to be unrelated to levels of Anxiety Sensitivity, Injury/illness Sensitivity or Pain Catastrophizing. Implications of the findings and recommendations for future research are discussed.

An experimental examination of catastrophizing-related interpretation bias for ambiguous facial expressions of pain using an incidental learning task

Individuals with pain-related concerns are likely to interpret ambiguous pain-related information in a threatening manner. It is unknown whether this interpretation bias also occurs for ambiguous pain-related facial expressions. This study examined whether individuals who habitually attach a catastrophic meaning to pain are characterized by negative interpretation bias for ambiguous pain-related facial expressions. Sixty-four female undergraduates completed an incidental learning task during which pictures of faces were presented, each followed by a visual target at one of two locations. Participants indicated target location by pressing one of two response keys. During the learning phase, happy and painful facial expressions predicted target location. During two test phases, morphed facial expressions of pain and happiness were added, equally often followed by a target at either location. Faster responses following morphs to targets at the location predicted by painful expressions compared to targets at the location predicted by happy expressions were taken to reflect pain-related interpretation bias. During one test phase, faces were preceded by either a safe or threatening context cue. High, but not low, pain-catastrophizers responded faster following morphs to targets at the location predicted by painful expressions than to targets at the other location (when participants were aware of the contingency between expression type and target location). When context cues were presented, there was no indication of interpretation bias. Participants were also asked to directly classify the facial expressions that were presented during the incidental learning task. Participants classified morphs more often as happy than as painful, independent of their level of pain catastrophizing. This observation is discussed in terms of differences between indirect and direct measures of interpretation bias.

Eating and inflicting pain out of boredom

In the present study it was investigated whether boredom promotes eating and if so, whether this effect likely reflects an increased drive for rewarding stimulation (positive reinforcement) or more plainly the drive to escape boredom (negative reinforcement). In the latter case, the valence of the stimulation should not matter and people might even be willing to look for negative stimulation, for instance to hurt oneself, just to escape boredom. In two parallel experiments, it was tested whether induced boredom promotes the consumption of chocolate (Experiment 1) and whether participants likewise are more inclined to self-administer electrocutaneous stimuli (Experiment 2). In both experiments, a total of 30 participants attended two separate sessions watching a documentary for 1 h (neutral condition) and a monotonous repetition of a single clip from the same documentary for 1 h (boring condition), in balanced order. During Experiment 1, participants had free access to M&Ms and during Experiment 2 participants could freely self-administer brief electrical shocks. It was found that participants ate more M&Ms when bored but also that they more readily self-administered electrical shocks when bored. It is concluded that eating when bored is not driven by an increased desire for satisfying incentive stimulation, but mainly by the drive to escape monotony.

The effects of experimental pain and induced optimism on working memory task performance

Abstract Background/aims Pain can interrupt and deteriorate executive task performance. We have previously shown that experimentally induced optimism can diminish the deteriorating effect of cold pressor pain on a subsequent working memory task (i.e., operation span task). In two successive experiments we sought further evidence for the protective role of optimism on pain-induced working memory impairments. We used another working memory task (i.e., 2-back task) that was performed either after or during pain induction. Methods Study 1 employed a 2 (optimism vs. no-optimism) × 2 (pain vs. no-pain) × 2 (pre-score vs. postscore) mixed factorial design. In half of the participants optimism was induced by the Best Possible Self (BPS) manipulation, which required them to write and visualize about a life in the future where everything turned out for the best. In the control condition, participants wrote and visualized a typical day in their life (TD). Next, participants completed either the cold pressor task (CPT) or a warm water control task (WWCT). Before (baseline) and after the CPT or WWCT participants working memory performance was measured with the 2-back task. The 2-back task measures the ability to monitor and update working memory representation by asking participants to indicate whether the current stimulus corresponds to the stimulus that was presented 2 stimuli ago. Study 2 had a 2 (optimism vs. no-optimism) × 2 (pain vs. no-pain) mixed factorial design. After receiving the BPS or control manipulation, participants completed the 2-back task twice: once with painful heat stimulation, and once without any stimulation (counterbalanced order). Continuous heat stimulation was used with temperatures oscillating around 1 °C above and 1 °C below the individual pain threshold. Results In study 1, the results did not show an effect of cold pressor pain on subsequent 2-back task performance. Results of study 2 indicated that heat pain impaired concurrent 2-back task performance. However, no evidence was found that optimism protected against this pain-induced performance deterioration. Conclusions Experimentally induced pain impairs concurrent but not subsequent working memory task performance. Manipulated optimism did not counteract pain-induced deterioration of 2-back performance. Implications It is important to explore factors that may diminish the negative impact of pain on the ability to function in daily life, as pain itself often cannot be remediated. We are planning to conduct future studies that should shed further light on the conditions, contexts and executive operations for which optimism can act as a protective factor.

Are individual levels of pain anxiety related to negative interpretation bias?: An examination using an ambiguous word priming task

Cognitive processes like attentional and interpretation biases have been suggested to play a vital role in the onset and exacerbation of chronic pain. Research consistently supports the occurrence of interpretation bias (IB) in pain patients and healthy individuals high in pain anxiety. Nevertheless, studies on the indirect assessment of IB or the relation between IB and responses to pain are limited. The present studies examined the association between indirect assessed IB and pain anxiety, while Study 2 additionally examined IB as a mediator in the relation between pain anxiety and pain responses.