Sex Differences in the Relationship Between Psychopathy and Cerebral Lateralization During Empathic Challenge

Abstract

Hemispherical dominance or cerebral lateralization is characterized as activity in the brain being elevated in one hemisphere more than the other, typically during presentations of affectively laden stimuli. The right hemisphere is associated with feelings of negative affect, while the left hemisphere is associated with positive emotions (Robinson and Price, 1982). Empathetic responses in relation to hemispheric dominance and the degree of psychopathy has not been examined in non-clinical populations, and sex of participant even less so. Social/emotional processing in females may differ from males; the human brain is sexually dimorphic, various structures being different between the sexes (Nopoulos et al., 2000). Using the ratio of alpha power between the left and right frontal cortices (F3 vs. F4) as an index of relative cerebral activity, we found a non-significant relationship between right hemisphere lateralization and psychopathy when viewing a highly empathic video of someone in distress. The correlation between LSRP scores and the left to right hemisphere ratio was not significant in females (p = .394 [-.199, .623]). The correlation between LSRP scores and the left to right hemisphere ratio was not significant in males, p = .919 [-.432, .337]. There was a non-significant relationship that showed females had a stronger LSRP and left-to-right alpha ratio (R² = 0.060, linear; R² =0.207, quadratic., see figure 1) compared to males R² = 0.001, linear; R² =0.052, quadratic., see figure 2), but significance was not reached.