Human Studies

The shared representations account of empathy suggests that sharing other people's emotions relies on neural processes similar to those engaged when directly experiencing such emotions. Recent research corroborated this by showing that placebo analgesia induced for first-hand pain resulted in reduced pain empathy and decreased activation in shared neural networks. However, those studies did not report any placebo-related variation of somatosensory engagement during pain empathy. The experimental paradigms used in these studies did not direct attention towards a specific body part in pain, which may explain the absence of effects for somatosensation. The main objective of this preregistered study was to implement a paradigm overcoming this limitation, and to investigate whether placebo analgesia may also modulate the sensory-discriminative component of empathy for pain. We induced a localized, first-hand placebo analgesia effect in the right hand of 45 participants by means of a placebo gel and conditioning techniques, and compared this to the left hand as a control condition. Participants underwent a pain task in the MRI scanner, receiving painful or non-painful electrical stimulation on their left or right hand, or witnessing another person receiving such stimulation. In contrast to a robust localized placebo analgesia effect for self-experienced pain, the empathy condition showed no differences between the two hands, neither for behavioral nor neural responses. We thus report no evidence for somatosensory sharing in empathy, while replicating previous studies showing overlapping brain activity in the affective-motivational component for first-hand and empathy for pain. Hence, in a more rigorous test aiming to overcome limitations of previous work, we again find no causal evidence for the engagement of somatosensory sharing in empathy. Our study refines the understanding of the neural underpinnings of empathy for pain, and the use of placebo analgesia in investigating such models.

Treatment based on the Fear-Avoidance (FA) model has been found to be effective with chronic low back pain (CLBP), and in-vivo exposure of fear evoking movements is proposed as a key change mechanism. Exposure tasks may be conducted in the session (in-session exposure; ISE), in other real life situations (between sessions exposure) as part of homework assignments, or both. Utilizing a randomized, controlled dismantling study design, the aim of this study was to examine the unique effects of ISE in FA-treatment of CLBP.

Exposure to a traumatic event is common among US adults, yet only a small fraction develops post-traumatic stress disorder (PTSD). Higher pain after a traumatic injury has been associated with higher PTSD symptomology and thus may be a risk factor. However, few studies have examined how pain during the period immediately after a trauma, referred to as the acute post trauma period, relates to later to PTSD outcomes.

Placebo effects may occur when it is known that an inert substance is given (i.e., open-label placebo). It is not yet clear whether these effects are similar to concealed (i.e. closed-label) placebo effects for itch, or whether nocebo effects can be induced under open-label conditions.

Clinical guidelines recommend that healthcare providers assist children to understand their experience of persistent pain, with pain science education a key component of clinical management in pediatric pain clinics. Currently, no tool exists to assess a child's concept of pain. The aim of this study was to develop such a tool and to evaluate its psychometric properties.

To investigate changes in analgesic use before and after supervised exercise therapy and patient education in patients with knee or hip osteoarthritis (OA).