Neural Correlates of Deficits in Humor Appreciation in Gelotophobics

Gelotophobics have social deficits in the form of relative humorlessness and heightened sensitivity to aggressive humor; however, little is known about the neural reward mechanisms for this group. The present study attempted to identify the neural substrates of responses to hostile and non-hostile jokes in gelotophobics and non-gelotophobics. Gelotophobics showed greater activation than did non-gelotophobics in the dorsal corticostriatal system, which comprises the dorsolateral prefrontal cortex and dorsal striatum, suggesting a higher degree of voluntary top-down cognitive control of emotion. As expected, gelotophobics showed less activation in the ventral mesocorticolimbic system (MCL) in response to both hostile and non-hostile jokes, suggesting a relative deficit in the reward system. Conversely, non-gelotophobics displayed greater activation than gelotophobics did in the MCL system, particularly for non-hostile jokes, which suggests a more robust bottom-up emotional response. In response to non-hostile jokes, non-gelotophobics showed greater activation in the ventral MCL reward system, which comprises the midbrain, amygdalae, nucleus accumbens, ventral anterior cingulate cortex, and insula. Psychophysiological interaction analyses further showed that gelotophobics exhibited diminished MCL activation in response to hostile jokes. These group differences may have important implications for our understanding of the neural correlates of social motivation and humor appreciation.