Contributed by Edward E. Smith, February 22, 2011 (sent for review October 05, 2010)
How similar are the experiences of social rejection and physical pain? Extant research suggests that a network of brain regions that support the affective but not the sensory components of physical pain underlie both experiences. Here we demonstrate that when rejection is powerfully elicited—by having people who recently experienced an unwanted break-up view a photograph of their ex-partner as they think about being rejected—areas that support the sensory components of physical pain (secondary somatosensory cortex; dorsal posterior insula) become active. We demonstrate the overlap between social rejection and physical pain in these areas by comparing both conditions in the same individuals using functional MRI. We further demonstrate the specificity of the secondary somatosensory cortex and dorsal posterior insula activity to physical pain by comparing activated locations in our study with a database of over 500 published studies. Activation in these regions was highly diagnostic of physical pain, with positive predictive values up to 88%. These results give new meaning to the idea that rejection “hurts.” They demonstrate that rejection and physical pain are similar not only in that they are both distressing—they share a common somatosensory representation as well.
Author contributions: E.K., W.M., E.E.S., and T.D.W. designed research; E.K. performed research; E.K., M.G.B., and T.D.W. analyzed data; and E.K., M.G.B., W.M., E.E.S., and T.D.W. wrote the paper.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1102693108/-/DCSupplemental.
*Although we did not observe bilateral activation in dpINS and OP1 in this subset of participants, we found no evidence of lateralization when we compared the β-values extracted from right and left OP1, and right and left dpINS (all, Fs < 0.318, ns). We suspect that failure to observe bilateral activations among this subset of participants in these ROIs may be an issue of power, as we observed bilateral activation in the full sample, which was double the size.
†Following this study, half the participants (n = 20) received a placebo manipulation and the other half did not (n = 20). All participants then engaged in the social rejection and physical pain tasks again. The results of this placebo manipulation on subsequent social rejection and physical pain-related neural activity are the focus of a subsequent article, and thus are not reported here. The between-subjects placebo vs. control manipulation was independent of all of the within-subjects effects that are the focus of the present article, and controlling for placebo vs. control manipulation at the group level did not qualitatively alter any of the results.
Freely available online through the PNAS open access option.
