Comedy can be divisive among people but requires integrative brain function in the individual. Doctors find it particularly interesting when a person’s sense of humour changes because neurological and psychiatric diseases disturb our sense of humour.
In the late 19th century, Herman Oppenheim and Moritz Jastrowitz described addiction to inappropriate joking and cheerfulness in patients with brain tumours.
“Witzelsucht”, from the German words for joke (Witz) and addiction (Sucht), refers to a compulsive need to make inappropriate jokes. “Moria of Jastrowitz” is a term that refers to childish or silly excitement. Witzelsucht and moria arise from brain tumours, strokes, infections, brain trauma, frontotemporal dementia and other lesions involving the frontal lobe of the brain (especially on the right side).
Interestingly, these patients don’t seem to find other people’s jokes funny but respond with uncontrollable mirth to their own gags. They do better with slapstick and puns than complex or unfamiliar humour; mostly enjoying simple, silly jokes.
The brain does not regard a sense of humour and laughter as the same thing. The former sometimes causes the latter, but in cases of pathological laughter, patients have fits of uncontrollable, excessive laughter in response to no stimulus or a trivial one. They may even burst into laughter when they are angry or sad, and sometimes abruptly switch between uncontrollable crying and laughing. Pathological laughter can result from brain injury and neurological diseases like strokes, amyotrophic lateral sclerosis, multiple sclerosis, and Parkinson’s Disease. A rare manifestation of epilepsy (gelastic epilepsy or laughing seizures) can also cause bursts of unprovoked laughter.
An ordinary sense of humour is changed by developmental or genetic conditions which display specific personality traits, such as Angelman or the “happy puppet” syndrome, Williams syndrome, and Down’s syndrome. Although autistics struggle to process social and emotional aspects of humour, they may retain some appreciation for physical comedy and slapstick.
I recall a pithy from one of my older professors. He frequently reminded us: “We don’t see things as they are; we see them as we are.” The same can be said of comedy. The meaning your brain attributes to a joke and how you respond to that joke tells a contemplative comic more about you than you may realize.