Unravelling the role of the opioid system in pain empathy

Wider research context / theoretical framework: Earlier social neuroscience studies have revealed overlapping brain activity during first-hand and empathic affective experiences, suggesting so-called shared representations. Recent insights pointed towards an involvement of the endogenous opioid system in
empathy for pain. Nevertheless, previously applied experimental manipulations lacked specificity and allowed for alternative explanations of the observed effects. The current project aims at taking the understanding of the neural bases of empathy to the next level. In a psychopharmacological neuroimaging
approach, we will test whether manipulations of the opioid system affect first-hand and empathic pain in similar ways.
Hypotheses / research questions / objectives: We expect that pharmacological manipulations of the opioid system will affect subjective ratings and neural correlates of pain and empathy for pain to a similar extent.
Confirmation of our hypotheses would provide unprecedentedly specific evidence for the involvement of the opioid system in empathy for pain. Beyond the more rigorous assessment of previous results, we plan to pinpoint a neural signature that commonly codes for first-hand and empathic pain.
Approach / methods: In two experiments with two functional magnetic resonance imaging (fMRI) sessions each, participants will perform an empathy for pain task, in which they and another person will receive painful electrical stimulation. In a double blind, placebo-controlled fashion, we will administer opioid receptor agonists (Buprenorphine) and antagonists (Naltrexone) to down- or up-regulate pain processing, and to investigate how this influences pain empathy and its neural correlates. We will employ a variety of fMRI analysis techniques, ranging from conventional mass-univariate to multivoxel pattern analyses. In addition, we will test possible pharmacological effects on resting-state functional connectivity and its relation to task effects.
Level of originality / innovation: The combination of highly specific pharmacological manipulations with direct tests of first-hand and empathic pain is at the forefront of current research in social cognitive neuroscience.
By way of our design and by applying novel analysis approaches, we intend to overcome previous methodological shortcomings. Thus, we expect substantial new insights that will inform models of shared representations and our understanding of how we represent other people’s affective states.
Primary researchers involved: PI Claus Lamm (http://scan-psy.univie.ac.at) from the University of Vienna (UV), a pioneer in the social neuroscience of empathy, will lead the project. Two postdocs (Markus Rütgen, Isabella Wagner) with strong experience in neuroscientific empathy research and fMRI analysis methods will support him. Collaborators Giorgia Silani (UV) and Predrag Petrovic (Karolinska Institutet) will strengthen the project with their background in empathy and psychopharmacology.