Mirth and laughter induced by electrical stimulation of the posterior insula

•Laughter occurred when stimulating posterior insula.•Laughter related to a variety of brain regions.•Progression of mirth in the insula contribute to laughter.•Posterior insula in involuntary pathway related to laughter. Laughter induced in the insula is uncommon. In this case-report we present a description of a patient with drug-resistant focal epilepsy for whom laughter with mirth was elicited when the posterior insula (PI) was stimulated by intracranial electrodes. We attempted to analyze the progression of laughter in the insula and suggest a possible pathway for the expression of laughter.