A popular psychological model suggests that humor involves detection and resolution of incongruity. Incongruity is generated when a prediction is not confirmed in the final part of a story. To comprehend humor, it is necessary to revisit the story, transforming an incongruous situation into a funny, congruous one. Bartolo et al. used cartoon pairs to elicit humor without language processing because previous studies involving verbal humor had been difficult to interpret.
Here is the cartoon pair:
They found activation of both the left and the right hemispheres when comparing funny versus nonfunny cartoons. In particular, as shown in Part A of the figure below, they found activation of the right inferior frontal gyrus (Brodman area 47, BA 47), the left superior temporal gyrus (BA 38), the left middle temporal gyrus (BA 21), and the left cerebellum. These areas had previously been implicated in a nonverbal task exploring attribution of intention. They suggest that the resolution of incongruity might occur through a process of intention attribution. Bartolo et al. also asked subjects to rate the funniness of each cartoon pair. A parametric analysis of Brain areas activated during humor appreciation (Part B of figure below)showed that the left amygdala (the small dot in center of the top two pictures in part B) was activated in relation to subjective amusement, suggesting a key role for the amygdala in giving humor an emotional dimension.