Anodal transcranial direct current stimulation of MPFC enhances humor processing

The purpose of this study was to investigate whether the comprehension of a specific type of humorous situation requires the involvement of brain regions associated to mentalization or Theory of Mind processing and if the electrical stimulation of these areas would facilitate the comprehension of humor. To this aim, we analyzed the effects of tDCS stimulation on the MPFC and rTPJ during the presentation of humorous and non-humorous comic strips. In particular, the stimulus set included strips containing humorous scenes that required ToM abilities in order to be comprehended (Humorous ToM), non-ToM humorous strips (Humorous non-ToM), non-humorous strips which were semantically coherent but not funny (Congruent), and non-humorous strips which were semantically incoherent (Incongruent). Results suggest that the MPFC appears to be involved in both humor processing and in the incongruity resolution process: MPFC stimulation improved the ability to identify a non-humorous incongruent element and to recognize the humorous element of the scene. On the other hand, RTPJ activity doesn't seem to be specifically involved in humorous processing network and appears to be more related to the ability to understand the cognitive element of a social context.