Periodic Reporting for period 2 - PAID (PAInful Decisions - How chronic pain affects daily decision-making)
Reporting period: 2024-08-01 to 2025-07-31
Summary of the context and overall objectives of the project
Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread pain, multiple tender points, fatigue, and impaired mental functioning. Best practice interventions for chronic pain typically include effortful exercise and long-term treatment – i.e. interventions that involve short-term costs (effort) with delayed benefit (improved pain and function). Problematically, adherence to these treatments is often low. While low adherence has typically been assumed to be due to low motivation, it is also possible that people with chronic pain may have altered decision-making related to delayed and effortful rewards. Understanding if long-term pain influences decision-making, what aspects of long-term pain contribute most to decision-making (e.g. emotional versus physical), and the neural underpinnings of these contributors, are essential given the clear relevance of altered decision-making to the adherence to evidence-based management strategies. Such knowledge could inform the development of novel interventions for FM.
The PAInful Decisions (PAID) project addresses these critical aspects by evaluating delay and effort attitudes in those experiencing FM and in a group of age- and sex-matched pain-free controls. Additionally, it investigates the unique role of emotions and bodily sensation perception as potential contributing factors to altered decision-making involving delayed and effortful gratification. PAID is a highly innovative and interdisciplinary project, integrating approaches from experimental psychology, behavioural economics, clinical practice, psychophysiology, and neuroimaging. This way, it comprehensively investigates the role of body-brain interactions in the context of chronic pain. Such a systematic, selective, and interdisciplinary approach to study decision-making in chronic pain is a considerable research challenge, yet the results have an essential meaning for patients’ lives and clinical practice, offering to move basic and applied science forward. The project’s scientific impact lies in contributing new scientific insights regarding the impact of chronic pain in decision-making in FM with interdisciplinary and multimodal approaches; generating an open-source database. The expected economic impact is in providing insights into better uptake, improved retention and adherence to interventions that are cornerstone to chronic pain management. Additionally, by disseminating the research outcomes widely, i.e. not only via scientific conferences and papers but also by targeting clinical audiences (patients and their families) as well as healthcare professionals, we will raise awareness of potential decision-making issues faced by patients with chronic pain.
The PAInful Decisions (PAID) project addresses these critical aspects by evaluating delay and effort attitudes in those experiencing FM and in a group of age- and sex-matched pain-free controls. Additionally, it investigates the unique role of emotions and bodily sensation perception as potential contributing factors to altered decision-making involving delayed and effortful gratification. PAID is a highly innovative and interdisciplinary project, integrating approaches from experimental psychology, behavioural economics, clinical practice, psychophysiology, and neuroimaging. This way, it comprehensively investigates the role of body-brain interactions in the context of chronic pain. Such a systematic, selective, and interdisciplinary approach to study decision-making in chronic pain is a considerable research challenge, yet the results have an essential meaning for patients’ lives and clinical practice, offering to move basic and applied science forward. The project’s scientific impact lies in contributing new scientific insights regarding the impact of chronic pain in decision-making in FM with interdisciplinary and multimodal approaches; generating an open-source database. The expected economic impact is in providing insights into better uptake, improved retention and adherence to interventions that are cornerstone to chronic pain management. Additionally, by disseminating the research outcomes widely, i.e. not only via scientific conferences and papers but also by targeting clinical audiences (patients and their families) as well as healthcare professionals, we will raise awareness of potential decision-making issues faced by patients with chronic pain.
Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far
The project comprised two main work packages (WP1 and WP2), combining behavioural and neuroimaging approaches to investigate how fibromyalgia (FM) affects decision-making processes related to effort, delay, and interoception.
WP1 – Behavioural study
The first part of the project involved a laboratory-based behavioural study comparing individuals with FM to age- and sex-matched controls. Participants engaged in three decision-making tasks in which they could earn real rewards (raffle tickets) by either exerting physical effort (walking on a treadmill), performing a cognitive effort task (short memory task), or waiting for a delayed outcome. Effort levels were individually calibrated to participants’ capacity to ensure comparability across groups. Additional questionnaires and behavioural tasks assessed bodily awareness and interpretation of bodily sensations.
The results revealed a specific alteration in attitudes towards physical effort among individuals with FM. They required higher levels of reward to engage in physically demanding tasks, particularly at higher effort intensities, compared to controls. Importantly, no differences were observed for cognitive effort discounting, suggesting that motivational deficits in FM are not general but domain-specific. Delay discounting results further supported this conclusion: FM participants were more willing to wait for delayed rewards, particularly at lower reward levels, indicating heightened motivation by outcomes rather than reduced overall motivation. Furthermore, the choice to engage in more effortful physical tasks was associated with higher self-reported anxiety, physical fatigue sensations, and alexithymia, highlighting a link between altered bodily awareness and decision-making in FM.
WP2 – Behavioural-fMRI study
The second part of the project employed a combined behavioural and neuroimaging approach. Twenty-five FM participants and 25 matched controls completed two effort discounting tasks inside the MRI scanner (physical effort: continuous button pressing; cognitive effort: memory-based), along with interoception and bodily perception measures.
Behaviourally, results were consistent with WP1: no group differences were found in cognitive effort discounting, and no significant differences emerged for physical effort in the scanner task. The lack of differences in physical effort may be related to the specific design of the scanner task, which required repetitive button-pressing rather than a naturalistic physical effort, such as walking. Together, these findings reinforce the conclusion that FM is not characterised by generalised motivational deficits.
In contrast, pronounced differences emerged in interoception and bodily state perception. While groups did not differ in interoceptive accuracy, confidence, or insight on the heartbeat counting task, FM participants reported greater interoceptive difficulties (Interoception Sensory Questionnaire) and showed reduced differentiation between emotional and non-emotional bodily states in the Body Mapping Task. These results indicate that FM is associated with altered interpretation and integration of bodily signals, which may contribute to pain experience and effort-related decision-making.
At the neural level, effort-based decision-making engaged a network spanning prefrontal regions (medial frontal gyrus, frontal pole, precentral gyrus), supramarginal gyrus, and insula, consistent with prior literature. No group differences were found during cognitive effort discounting, mirroring behavioural findings. However, during physical effort discounting, controls showed greater activation than FM participants in the lateral occipital cortex, a region implicated in uncertainty evaluation during decision-making. This suggests that FM participants may engage different neural mechanisms when assessing the costs and benefits of physically effortful actions.
Main achievements
The project provides novel evidence that motivational alterations in FM are domain-specific rather than general, affecting decisions involving physical effort but not cognitive effort. These changes appear closely linked to altered perception and interpretation of bodily sensations rather than to deficits in interoceptive accuracy. The neuroimaging results identify potential neural mechanisms underlying these differences, highlighting altered recruitment of decision-making circuits in FM. Together, these findings contribute to a more nuanced understanding of how disrupted body–brain communication shapes daily decision-making in chronic pain conditions.
WP1 – Behavioural study
The first part of the project involved a laboratory-based behavioural study comparing individuals with FM to age- and sex-matched controls. Participants engaged in three decision-making tasks in which they could earn real rewards (raffle tickets) by either exerting physical effort (walking on a treadmill), performing a cognitive effort task (short memory task), or waiting for a delayed outcome. Effort levels were individually calibrated to participants’ capacity to ensure comparability across groups. Additional questionnaires and behavioural tasks assessed bodily awareness and interpretation of bodily sensations.
The results revealed a specific alteration in attitudes towards physical effort among individuals with FM. They required higher levels of reward to engage in physically demanding tasks, particularly at higher effort intensities, compared to controls. Importantly, no differences were observed for cognitive effort discounting, suggesting that motivational deficits in FM are not general but domain-specific. Delay discounting results further supported this conclusion: FM participants were more willing to wait for delayed rewards, particularly at lower reward levels, indicating heightened motivation by outcomes rather than reduced overall motivation. Furthermore, the choice to engage in more effortful physical tasks was associated with higher self-reported anxiety, physical fatigue sensations, and alexithymia, highlighting a link between altered bodily awareness and decision-making in FM.
WP2 – Behavioural-fMRI study
The second part of the project employed a combined behavioural and neuroimaging approach. Twenty-five FM participants and 25 matched controls completed two effort discounting tasks inside the MRI scanner (physical effort: continuous button pressing; cognitive effort: memory-based), along with interoception and bodily perception measures.
Behaviourally, results were consistent with WP1: no group differences were found in cognitive effort discounting, and no significant differences emerged for physical effort in the scanner task. The lack of differences in physical effort may be related to the specific design of the scanner task, which required repetitive button-pressing rather than a naturalistic physical effort, such as walking. Together, these findings reinforce the conclusion that FM is not characterised by generalised motivational deficits.
In contrast, pronounced differences emerged in interoception and bodily state perception. While groups did not differ in interoceptive accuracy, confidence, or insight on the heartbeat counting task, FM participants reported greater interoceptive difficulties (Interoception Sensory Questionnaire) and showed reduced differentiation between emotional and non-emotional bodily states in the Body Mapping Task. These results indicate that FM is associated with altered interpretation and integration of bodily signals, which may contribute to pain experience and effort-related decision-making.
At the neural level, effort-based decision-making engaged a network spanning prefrontal regions (medial frontal gyrus, frontal pole, precentral gyrus), supramarginal gyrus, and insula, consistent with prior literature. No group differences were found during cognitive effort discounting, mirroring behavioural findings. However, during physical effort discounting, controls showed greater activation than FM participants in the lateral occipital cortex, a region implicated in uncertainty evaluation during decision-making. This suggests that FM participants may engage different neural mechanisms when assessing the costs and benefits of physically effortful actions.
Main achievements
The project provides novel evidence that motivational alterations in FM are domain-specific rather than general, affecting decisions involving physical effort but not cognitive effort. These changes appear closely linked to altered perception and interpretation of bodily sensations rather than to deficits in interoceptive accuracy. The neuroimaging results identify potential neural mechanisms underlying these differences, highlighting altered recruitment of decision-making circuits in FM. Together, these findings contribute to a more nuanced understanding of how disrupted body–brain communication shapes daily decision-making in chronic pain conditions.
Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)
The project advanced knowledge of decision-making and interoception in chronic pain by providing a fine-grained characterisation of how fibromyalgia (FM) affects motivation and bodily awareness. Prior work in chronic pain often assumed generalised motivational deficits; however, our findings demonstrate a more nuanced picture. Specifically, individuals with FM showed:
- Domain-specific alterations in motivation: reduced willingness to engage in physically effortful tasks unless offered higher rewards, while performance on cognitive effort tasks and delay discounting suggested intact or even enhanced motivation in other domains.
- Altered bodily awareness rather than accuracy deficits: FM participants did not differ in interoceptive accuracy but reported greater subjective difficulties in perceiving and differentiating bodily signals. This highlights the importance of perceptual and interpretative aspects of interoception in chronic pain, going beyond earlier models focused narrowly on accuracy.
- Novel neural mechanisms: fMRI results identified altered recruitment of decision-making circuits during physical effort discounting, with controls showing stronger activation in the lateral occipital cortex, a region linked to uncertainty evaluation. This provides one of the first demonstrations of altered neural substrates of effort-based decision-making in FM.
Potential impacts
These findings have implications beyond academic knowledge. By disentangling motivation from bodily awareness, the project opens avenues for:
- Targeted interventions: Development of therapies aimed at recalibrating bodily perception and interpretation (e.g. interoceptive training, biofeedback) rather than attempting to increase general motivation.
- Clinical stratification: Identifying patients with altered bodily awareness as a subgroup who may benefit from tailored treatment approaches.
- Cross-domain relevance: Since altered interoception is also implicated in other conditions (e.g. depression, anxiety, addiction), these results provide transferable insights into body–brain interactions across disorders.
Key needs for further uptake
To maximise impact, further research is required to:
- Test whether interoceptive training can modify effort-related decision-making in FM.
- Validate the observed neural markers in larger, multi-site samples.
- Translate laboratory paradigms into ecologically valid assessments of decision-making in daily life.
- Explore applicability of findings to other nociplastic pain conditions (e.g. irritable bowel syndrome) and comorbidities such as mood or substance use disorders.
Overall, the project provides results that go beyond the state of the art by challenging existing assumptions about motivation in chronic pain and by identifying altered bodily perception as a key mechanism influencing decision-making.
- Domain-specific alterations in motivation: reduced willingness to engage in physically effortful tasks unless offered higher rewards, while performance on cognitive effort tasks and delay discounting suggested intact or even enhanced motivation in other domains.
- Altered bodily awareness rather than accuracy deficits: FM participants did not differ in interoceptive accuracy but reported greater subjective difficulties in perceiving and differentiating bodily signals. This highlights the importance of perceptual and interpretative aspects of interoception in chronic pain, going beyond earlier models focused narrowly on accuracy.
- Novel neural mechanisms: fMRI results identified altered recruitment of decision-making circuits during physical effort discounting, with controls showing stronger activation in the lateral occipital cortex, a region linked to uncertainty evaluation. This provides one of the first demonstrations of altered neural substrates of effort-based decision-making in FM.
Potential impacts
These findings have implications beyond academic knowledge. By disentangling motivation from bodily awareness, the project opens avenues for:
- Targeted interventions: Development of therapies aimed at recalibrating bodily perception and interpretation (e.g. interoceptive training, biofeedback) rather than attempting to increase general motivation.
- Clinical stratification: Identifying patients with altered bodily awareness as a subgroup who may benefit from tailored treatment approaches.
- Cross-domain relevance: Since altered interoception is also implicated in other conditions (e.g. depression, anxiety, addiction), these results provide transferable insights into body–brain interactions across disorders.
Key needs for further uptake
To maximise impact, further research is required to:
- Test whether interoceptive training can modify effort-related decision-making in FM.
- Validate the observed neural markers in larger, multi-site samples.
- Translate laboratory paradigms into ecologically valid assessments of decision-making in daily life.
- Explore applicability of findings to other nociplastic pain conditions (e.g. irritable bowel syndrome) and comorbidities such as mood or substance use disorders.
Overall, the project provides results that go beyond the state of the art by challenging existing assumptions about motivation in chronic pain and by identifying altered bodily perception as a key mechanism influencing decision-making.