Money or funny: Effective connectivity during service recovery with a DCM-PEB approach

The differential processing of verbal jokes by neural substrates in indigenous and Han Chinese populations: An fMRI study

Limited research has been conducted on humor among the Taiwanese indigenous (IND) population. This study attempted to identify the differential neural correlates of humor comprehension and appreciation between IND and Han Chinese (HAN) populations. Each participant was presented with jokes and non-jokes. IND participants when encountered with jokes displayed a greater activation of the mesolimbic dopaminergic reward system, including the amygdala, midbrain, and nucleus accumbens than HAN participants. This suggests a more pleasurable response and appreciation of humor. The IND group also displayed greater activation in the right temporoparietal junction (rTPJ) than HAN, suggesting that the IND group may experience a greater sense of novelty and be more involved in social understanding, thus exhibiting greater humor appreciation. In terms of humor comprehension, both IND and HAN showed greater activation in the superior temporal gyrus (STG) and dorsal anterior cingulate cortex (dACC). IND exhibited greater activation in the anterior STG (aSTG), while HAN showed greater activation in the posterior STG (pSTG). This suggests that the IND tends to integrate emotional messages, whereas the HAN focuses on comprehending semantic cognitive information. Interestingly, HAN did not show any greater activation than IND in terms of appreciation of humor. These group disparities have substantial implications for advancing our knowledge of the neural mechanisms underlying humor comprehension and appreciation.

Amygdala-frontoparietal effective connectivity in creativity and humor processing

Although both creativity and humor elicit experiences of surprise followed by appreciation, it remains unknown whether shared or distinct patterns of effective connectivity are involved in their processing. The present fMRI study used dynamic causal modeling and parametrical empirical Bayes analysis to examine the effective connectivity between the amygdala and frontoparietal network during two-stage creativity and humor processing. We examined processing during the setup and punch line stages for creativity and humor, including typical forms (alternate uses for creativity and incongruity-resolution humor), atypical forms (aesthetic uses for creativity and nonsense humor), and baseline forms. Our focus was on the mesolimbic pathway during the punch line stage. We found that the amygdala plays a key role in expectation violation and appreciation. Broadly, amygdala-to-IFG connectivity was important for evaluating typical and atypical forms of both creativity and humor, while amygdala-to-precuneus connectivity was involved in evaluating typical forms. Amygdala-to-IFG connectivity was involved in the expectation violation to resolution stage of processing for typical and atypical forms of creativity and humor. Amygdala-to-precuneus connectivity was involved in processing the novelty and usefulness of typical forms of creativity (alternate uses) and understanding others' intentions in typical forms of humor (incongruity-resolution). Interestingly, VTA-to-amygdala connectivity was involved in processing the appreciation of both typical (incongruity-resolution humor) and atypical (nonsense humor) forms of humor while amygdala-to-VTA connectivity was involved in processing the appreciation of atypical (aesthetic uses) forms of creativity. Altogether, these findings suggest that the amygdala and frontoparietal circuitry are critical for creativity and humor processing.

Effective connectivity of the amygdala during the consumption of erotic, sexual humor, and monetary rewards with a DCM-PEB approach

While a large body of research exists on the processing of monetary rewards, less is known about sexual reward processing. This study aimed to identify effective connectivity for the consumption of sexual (erotic and sexual humor) and non-sexual (monetary) rewards, using dynamic causal modeling and parametric empirical Bayes with subjective hedonic ratings included. Our results support the importance of the amygdala for sexual humor amusement, the nucleus accumbens (NAc) for monetary rewards, and the lateral orbitofrontal cortex (lOFC) for erotic pleasure. The amygdala, NAc, and lOFC are major dopaminergic targets with known roles in the reward circuitry. Appreciating sexual humor was associated with ventral tegmental area (VTA) to amygdala connectivity. Enjoying monetary gains was associated with VTA-to-NAc and amygdala-to-NAc connectivity. The mesolimbic dopamine system originates in the VTA and sends major projections to the amygdala and NAc. Specifically, sexual humor appreciation was associated with effective connectivity from the ventromedial prefrontal cortex (vmPFC) to the amygdala, suggesting that subjective pleasure triggers activation of the vmPFC which exerts an excitatory influence on the amygdala. Unexpectedly, processing pleasure from monetary gains was linked to VTA-to-vmPFC connectivity, rather than the expected vmPFC-to-NAc connectivity. Importantly, we identified core roles for the amygdala. Sexual humor appreciation was associated with VTA-to-amygdala and vmPFC-to-amygdala effective connectivity, while we found amygdala-to-lOFC connectivity for erotic pleasure and amygdala-to-NAc connectivity for pleasure from monetary gains. Our findings represent an important step in understanding how effective connectivity in the mesocorticolimbic-amygdala circuitry differs for processing the consumption of sexual and monetary rewards.