Context-prosody interaction in sarcasm comprehension: A functional magnetic resonance imaging study

During conversation, sarcasm is perceived as an incongruity between the context, content, and prosody of the utterance. We hypothesized that prosody modifies the context‒content incongruity effect. Thus, we conducted a functional magnetic resonance imaging study with an auditory sarcasm detection task in 22 healthy adult participants. The participants listened to a short conversation according to which they had done either a good or bad deed, about which their conversational partner made a positive comment. When the context was positive (congruent with the content of utterance), positive prosody lessened the sarcasm rating, whereas negative prosody enhanced this rating. When the context was negative, the positive prosody effect disappeared, while negative prosody increased the sarcasm rating. Thus, context‒content incongruity is the primary determinant of sarcasm comprehension; and is modified by prosody in a context-dependent manner. Neuroimaging results showed that the context‒content incongruity effect was notable in the cerebellum and the mentalizing network, representing what was uttered in a particular context. The content‒prosody incongruity effect was observed in the bilateral amygdala, representing the manner of utterance. The interaction between these incongruity effects was found in the bilateral dorsolateral prefrontal cortex, extending to the inferior frontal gyrus and the salience network, including the anterior insular cortex and the caudal part of the dorso-medial prefrontal cortex. These findings indicate that two distinct incongruity detection systems for sarcasm comprehension are integrated in the prefrontal cortices through the salience network.