Insula and somatosensory cortical myelination and iron markers underlie individual differences in empathy

The behavioral data with demographics (age, gender) and interpersonal reactivity index (IRI) scores for all participants. Paper Abstract: Empathy is a key component of our ability to engage and interact with others. In recent years, the neural mechanisms underlying affective and cognitive empathy have garnered intense interest. This work demonstrates that empathy for others depends upon similar neural mechanisms as when we ourselves experience an empathized-with emotion (e.g., pain). Individuals vary markedly in their ability to empathize with others, which predicts the tendency to help others and relates to individual differences in neuroanatomy. Here, we use a newly developed, high-resolution (800 µm isotropic), quantitative MRI technique to better elucidate the neurobiological mechanisms underpinning individual differences in empathy and neuroanatomy. Our findings extend previous studies of the neuroanatomical correlates of cognitive and affective empathy. In particular, individual differences in cognitive empathy were associated with markers of myeloarchitectural integrity of the insular cortex while affective empathy was predicted by a marker of iron content in second somatosensory cortex. These results indicate novel biomarkers of empathy, suggesting that microstructural features of brain areas previously associated with interoceptive and bodily self-awareness are crucial for understanding the mental and emotional states of others. Further, these results may indicate a previously unappreciated neurobiological mechanism underlying socio-economic or stress-related factors in the development of empathy.