Can the Neural Representation of Physical Pain Predict Empathy for Pain in Others?

The question of whether physical pain and vicarious pain have some shared neural substrates is unresolved. Whilst most studies have shown overlapping regions of brain activity to these two states this need not reflect shared substrates at the voxel level or below. Krishnan et al. (2016) found that physical and vicarious pain are represented by dissociable multivariate brain patterns by creating biomarkers for physical pain (Neurologic Pain Signature, NPS) and vicarious pain (Vicarious Pain Signature, VPS) respectively. In the current research, the NPS and VPS were applied to three fMRI datasets (one new, two published) relating to vicarious pain which focused on between-subject differences in vicarious pain (Datasets 1 and 3, N = 40 and 65 participants) and within-subject manipulations of perspective taking (Dataset 2，N= 71 participants). Results show that (1) NPS can distinguish brain responses to images of pain versus no-pain and to a greater extent in vicarious pain responders who report experiencing pain when observing pain, (2) VPS can distinguish brain responses to images of pain versus no-pain only during self-perspective instructions. This study suggests that the NPS (created to detect physical pain) is, under some circumstances, sensitive to vicarious pain and that the VPS (created to detect vicarious pain) is not a generalizable biomarker of vicarious pain.