White matter pathways associated with empathy in females: A DTI investigation

Empathy is a component of social cognition that allows us to understand, perceive, experience, and respond to the emotional state of others. In this study, we seek to build on previous research that suggests that sex and hormone levels may impact white matter microstructure. These white matter microstructural differences may influence social cognition. We examine the fractional anisotropy (FA) of white matter pathways associated with the complex human process of empathy in healthy young adult females during the self-reported luteal phase of their menstrual cycle. We used tract-based spatial statistics to perform statistical comparisons of FA and conducted multiple linear regression analysis to examine the strength of association between white matter FA and scores on the Empathy Quotient (EQ), a self-report questionnaire in which individuals report how much they agree or disagree with 60 statements pertaining to their empathic tendencies. Results identified a significant negative relationship between EQ scores and FA within five clusters of white matter: in the left forceps minor/body of the corpus callosum, left corticospinal tract, intraparietal sulcus/primary somatosensory cortex, superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus/forceps minor. These consistent findings across clusters suggest that lower self-reported empathy is related to higher FA across healthy young females in specific white matter regions during the menstrual luteal phase. Future research should seek to examine if self-reported empathy varies across the menstrual cycle, using blood samples to confirm cycle phase and hormone levels.