Cerebral events associated with detection and resolution of humorous incongruity

Humor is a commonplace and integral part of one’s everyday life, including but not limited to social interactions. Cognitive models of humor processing have been proposed where there is first detection of incongruity followed by resolution that is, at the final step during the comprehension and elaboration of humor, found amusing. Neuroimaging studies have identified a number of brain structures activated during comprehension of humor, but the cerebral events specifically underlying incongruity detection and incongruity resolution have remained less well known.

In their recent study Chan et al. (2013) investigated the neural basis of humorous incongruity detection and resolution in 22 healthy volunteers who were presented with unfunny, non-humorous nonsensical, and funny stories during event-related functional magnetic resonance imaging. Specifically, the stories consisted of setup and punch line parts. The punch line was altered in the unfunny and non-humorous nonsensical stimuli so that the humorous resolution was removed. The unfunny stimuli provided a punch line that was congruent with the setup and the non-humorous nonsensical stimuli provided a punch line that was incongruent with the setup yet lacked the humorous resolution. Hemodynamic responses were then contrasted to elucidate brain structures associated with incongruence detection and resolution processes.

The authors observed that detection of incongruity was associated with stronger hemodynamic responses in the right middle temporal and middle frontal gyri, with ratings of surprisingness of the punch lines further predicting activity of the right middle temporal gyrus. Their results further indicated that semantic selection and integration associated with incongruity resolution involved inferior frontal gyri bilaterally as well as left superior frontal gyrus and inferior parietal lobule. Taken together, these results very nicely elucidate the differential cerebral events that underlie detection and resolution of incongruity during humor comprehension. 

Reference: Chan YC, Chou TL, Chen HC, Yeh YC, Lavallee JP, Liang KC, Chang KE. Towards a neural circuit model of verbal humor processing: an fMRI study of the neural substrates of incongruity detection and resolution. Neuroimage (2013) 66: 169–176. http://dx.doi.org/10.1016/j.neuroimage.2012.10.019