Nathalie Claes

Competing goals attenuate avoidance behavior in the context of pain

UNLABELLED Current fear-avoidance models consider pain-related fear as a crucial factor in the development of chronic pain. However, pain-related fear often occurs in a context of multiple, competing goals. This study investigated whether pain-related fear and avoidance behavior are attenuated when individuals are faced with a pain avoidance goal and another valued but competing goal, operationalized as obtaining a monetary reward. Fifty-five healthy participants moved a joystick toward different targets. In the experimental condition, a movement to one target (conditioned stimulus [CS+]) was followed by a painful unconditioned stimulus (pain-US) and a rewarding unconditioned stimulus (reward-US) on 50% of the trials, whereas the other movement (nonreinforced conditioned stimulus [CS-]) movement was not. In the control condition, the CS+ movement was followed by the pain-US only. Results showed that pain-related fear was elevated in response to the CS+ compared to the CS- movement, but that it was not influenced by the reward-US. Interestingly, participants initiated a CS+ movement slower than a CS- movement in the control condition but not in the experimental condition. Also, in choice trials, participants performed the CS+ movement more frequently in the experimental than in the control condition. These results suggest that the presence of a valued competing goal can attenuate avoidance behavior. PERSPECTIVE The current study provides experimental evidence that both pain and competing goals impact on behavioral decision making and avoidance behavior. These results provide experimental support for treatments of chronic pain that include an individuals pursuit of valuable daily life goals, rather than limiting focus to pain reduction only.

Pain-avoidance versus reward-seeking: an experimental investigation.

Abstract According to fear-avoidance models, a catastrophic interpretation of a painful experience may give rise to pain-related fear and avoidance, leading to the development and maintenance of chronic pain problems in the long term. However, little is known about how exactly motivation and goal prioritization play a role in the development of pain-related fear. This study investigates these processes in healthy volunteers using an experimental context with multiple, competing goals. In a differential human fear-conditioning paradigm, 57 participants performed joystick movements. In the control condition, one movement (conditioned stimulus; CS+) was followed by a painful electrocutaneous unconditioned stimulus (pain-US) in 50% of the trials, whereas another movement (nonreinforced conditioned stimulus; CS−) was not. In the experimental condition, a reward in the form of lottery tickets (reward-US) accompanied the presentation of the pain-US. Participants were classified into 3 groups, as a function of the goal, they reported to be the most important: (1) pain-avoidance, (2) reward-seeking, and (3) both goals being equally important. Results indicated that neither the reward co-occurring with pain nor the prioritized goal modulated pain-related fear. However, during subsequent choice trials, participants selected the painful movement more often when the reward was presented compared with the context in which the reward was absent. The latter effect was dependent on goal prioritization, with more frequent selections in the reward-seeking group, and the least selections in the pain-avoidance group. Taken together, these results underscore the importance of competing goals and goal prioritization in the attenuation of avoidance behavior.

Comparing counterconditioning and extinction as methods to reduce fear of movement-related pain

UNLABELLED Cognitive-behavioral treatments for chronic pain typically target pain-related fear; exposure in vivo is a common treatment focusing on disconfirming harm expectancy of feared movements. Exposure therapy is tailored on Pavlovian extinction; an alternative fear reduction technique that also alters stimulus valence is counterconditioning. We compared both procedures to reduce pain-related fear using a voluntary joystick movement paradigm. Participants were randomly allocated to the counterconditioning or extinction group. During fear acquisition, moving the joystick in 2 directions (conditioned stimulus [CS+]) was followed by a painful electrocutaneous stimulus (pain-unconditioned stimulus [US]), whereas moving the joystick in 2 other directions was not (CS-). During fear reduction, 1 CS+ was extinguished, but another CS+ was still followed by pain in the extinction group; in the counterconditioning group, 1 CS+ was extinguished and followed by a monetary reward-US, and another CS+ was followed by both USs (pain-US and reward-US). The results indicate that counterconditioning effectively reduces pain-related fear but that it does not produce deeper fear reduction than extinction. Adding a reward-US to a painful movement attenuated neither fear nor the intensity/unpleasantness of the pain. Both procedures changed stimulus valence. We contend that changing the affective valence of feared movements might improve fear reduction and may prevent relapse. PERSPECTIVE This article reports no immediate differences between counterconditioning and extinction in reducing pain-related fear in the laboratory. Unexpectedly, both methods also altered stimulus valence. However, we cautiously suggest that methods explicitly focusing on altering the affective valence of feared movements may improve the long-term effectiveness of fear reduction and prevent relapse.

Pain in context : Cues predicting a reward decrease fear of movement related pain and avoidance behavior

Previous research shows that goal-directed behavior might be modulated by cues that predict (dis)similar outcomes. However, the literature investigating this modulation with pain outcomes is scarce. Therefore, this experiment investigated whether environmental cues predicting pain or reward modulate defensive pain responding. Forty-eight healthy participants completed a joystick movement task with two different movement orientations. Performing one movement was associated with a painful stimulus, whereas performance of another movement was associated with reward, i.e. lottery tickets. In a subsequent task, participants learned to associate three different cues withpain, reward, or neither of the two. Next, these cues were integrated in the movement task. This study demonstrates that in general, aversive cues enhance and appetitive cues reduce pain-related fear. Furthermore, we found that incongruence between the outcomes predicted by the movement and the cue results in more oscillatory behavior, i.e., participants were more willing to perform a painful movement when a cue predicting reward was simultaneously presented, and vice versa. Similarly, when given a choice, participants preferred to perform the reward movement, unless there was an incongruence between the outcomes predicted by the movements and cues. Taken together, these results provide experimental evidence that environmental cues are capable of modulating pain-related fear and avoidance behavior.

Reinstatement after human feature-positive discrimination learning

In two experiments, using an online conditioned suppression task, we investigated the possibility of reinstatement of extinguished feature-target compound presentations after sequential feature-positive discrimination training in humans. Furthermore, given a hierarchical account of Pavlovian modulation (e.g., Bonardi, 1998; Bonardi and Jennings, 2009), we predicted A-US reinstatement to be stronger than US-only reinstatement. In Experiment 1, participants learned a sequential feature-positive discrimination (X→A+|A-), which was subsequently extinguished (X→A-). During the following reinstatement phase, group US-only received US-only presentations (not signalled), group A-US received A-US presentations, and the Control group received exposure to the context, but no CSs or USs, for an equal amount of time. Reinstatement of differential X→A/A responding was observed in the US-only group but not in the Control or A-US groups. Although differential X→A/A responding was not significant in group A-US, responding to the X→A compound was significantly stronger compared to that in group US-only. Hence, it could be the case the group A-US showed stronger reinstatement, but that differential responding was abolished due to excitation gained by A. Experiment 2 was set up to circumvent the acquired excitation of A by testing transfer of the feature after A-US reinstatement to a different target, B. Participants acquired two discriminations, X→A/A and Y→B/B, of which X→A was then extinguished. Subsequently, group A-US received reinforced presentations of A during a reinstatement phase while group Control received exposure to the context. Final testing of the novel X→B compound was hypothesized to show higher responding in group A-US than in group Control, but findings of this approach were limited due to acquired equivalence and/or perceptual factors causing a secondary extinction effect. We conclude to have obtained clear evidence in favour of reinstatement of differential responding after human Feature-Positive discrimination training and subsequent compound extinction, but no evidence in favour of A-US presentations being a stronger trigger for reinstatement than are US-only presentations.

De rol van angst bij pijn : theoretische aspecten

Chronische pijn wordt tegenwoordig vanuit een biopsychosociaal perspectief benaderd, met aandacht voor zowel biologische, psychologische als sociale factoren. Een van de invloedrijkste biopsychosociale modellen voor chronische pijn is het vreesvermijdingsmodel. Volgens dit model is pijngerelateerde angst – oftewel een vaak buitensporige vermijdingsreactie op geanticipeerde pijn – een prominente factor in zowel de ontwikkeling als het behoud van chronische pijnproblemen. Deze pijngerelateerde angst komt meestal tot stand via associatieve leerprocessen, namelijk via pavloviaanse ofwel instrumentele conditionering, rechtstreeks contact, observatie van anderen, of verbale informatie, en is meetbaar aan de hand van verbale, gedragsmatige en psychofysiologische responsen. Pijngerelateerde angst leidt niet alleen tot vermijding van pijnlijke activiteiten, maar kan ook generaliseren tot een veralgemeende inactiviteit, die vaak gepaard gaat met een negatief affect. Door de zeer grote invloed van de angst voor pijn op het dagelijks leven is het reduceren van pijngerelateerde angst vaak een doelwit van behandelingen die patienten met pijn trachten te activeren. Vaak wordt een beroep gedaan op extinctieprocedures, waarbij de patient wordt blootgesteld aan de angst uitlokkende stimuli; dit stelt hem in staat de verwachting dat er catastrofale gevolgen optreden, uit te dagen. Exposure wordt beschouwd als het klinische equivalent van een typische extinctieprocedure.