Differential neural substrates for responding to monetary, sexual humor, and erotic rewards.

Sexual humor involves neural mechanisms related to both humor and sexual arousal. However, evidence on the role of the amygdala in processing sexual humor is lacking. Unlike erotic stimuli that directly involve a biological drive, sexual humor gains its value through learned associations. Processes related to responding to erotic versus monetary rewards have been identified in the lateral orbitofrontal cortex (lOFC) along a postero-anterior axis, but it is less clear whether these processes are also active during the appreciation of sexual humor. Results showed the processing of sexual humor appreciation in the amygdala. Psychophysiological interaction (PPI) analysis further identified functional connectivity in the amygdala-midbrain coupling during sexual humor versus monetary gains appreciation. The present study provides evidence demonstrating roles for the posterior OFC (pOFC) and anterior OFC (aOFC) in distinguishing between sexual (sexual humor and erotic) and non-sexual (monetary) rewards. The experience of sexual pleasure induced by erotic rewards involves phylogenetically and ontogenetically older regions in the pOFC, while the experience of receiving monetary gains involves the aOFC. This study also provides additional insights into sexual humor appreciation in the pOFC, with findings of a postero-anterior dissociation in the processing of sexual humor appreciation. PPI analysis revealed functional connectivity in the pOFC-amygdala coupling in response to both types of sexual rewards versus monetary rewards. Together, our results suggest that the amygdala serves as a reward hub, especially in processing sexual humor versus monetary gains appreciation. Functional connectivity analysis showed amygdala-midbrain and pOFC-amygdala coupling during the appreciation of sexual humor.