Neural responses to perceiving suffering in humans and animals

The human ability to perceive and understand others' suffering is critical to reinforcing and maintaining our social bonds. What is not clear, however, is the extent to which this generalizes to nonhuman entities. Anecdotal evidence indicates that people may engage in empathy-like processes when observing suffering nonhuman entities, but psychological research suggests that we more readily empathize with those to whom we are closer and more similar. In this research, we examined neural responses in participants while they were presented with pictures of human versus dog suffering. We found that viewing human and animal suffering led to large overlapping regions of activation previously implicated in empathic responding to suffering, including the anterior cingulate gyrus and anterior insula. Direct comparisons of viewing human and animal suffering also revealed differences such that human suffering yielded significantly greater medial prefrontal activation, consistent with high-level theory of mind, whereas animal suffering yielded significantly greater parietal and inferior frontal activation, consistent with more semantic evaluation and perceptual simulation.