Integration of cognitive and affective networks in humor comprehension.

Humor comprehension is a complex process that requires the detection and resolution of the incongruity, eliciting a positive feeling of mirth or reward. We conducted a functional magnetic resonance imaging (fMRI) study to identify the key factors involved in this complex process. To reduce the influence of other factors, we utilized a group of sentences that were nearly identical across conditions (i.e., the first two sentences and the punch line were identical, but the third sentence was different). We found that the punch line (target sentence) in the funny condition induced a perception of funniness and elicited greater activation in language and semantic neural networks, which have been implicated in comprehension processing (i.e., incongruity detection and resolution). We also found increased activation in the mesolimbic reward regions, which have been implicated in the experience of positive rewards in the funny condition. Psycho-physiological interaction analyses revealed that language and semantic regions, such as inferior frontal gyrus (IFG), middle temporal gyrus (MTG), superior temporal gyrus (STG), superior frontal gyrus (SFG), and inferior parietal lobule (IPL) are simultaneously activated during humor comprehension processing. These analyses also revealed that the right MTG, the left IPL, and IFG showed enhanced connectivity with the midbrain. Our findings suggest that these networks play a central role in incongruity detection and resolution, as well as in positive emotional response.