Role of Brain in Evoking Laughter

Laughter is a physical experience. While there is often an awareness of the cause of our laughter, this awareness usually comes after the laughter itself. The role of the brain in laughter is one that is still not fully understood although there is ongoing research in this area.

Spontaneous laughter is a motor reflex produced by the co-ordinated contraction of 15 facial muscles in a stereotyped pattern and accompanied by altered breathing.


Research at the College of William and Mary in Williamsburg Virginia has traced the pattern of brainwave activity in response to a joke. Electroencephalograms (EEG) were taken while subjects were presented with humorous material. The pattern that was noticed was:

1. The left side of the cortex analysed the words and structure of the material.
2. The frontal lobe, which is involved in social & emotional responses springs into action.
3. The right hemisphere of the cortex carries out the intellectual analysis required to understand the joke.
4. Brainwave activity spreads to the sensory processing areas of the occipital lobe.
5. Stimulation of the motor sections brings about the physical response, i.e. laughter.

So, unlike emotional responses, which are seen to be confined to specific areas of the brain, responses to humorous material and the reaction of laughter take place in many regions of the brain.


Prathiba Shammi, a nueropsychologist has also undertaken some research into the area of the relationship between laughter and the brain. The research was part of a joint study by the University of Toronto and Baycrest Centre for Geriatric Care in Toronto.

The study involved examining the response to humour by subjects who had experienced brain damage. Patients with damage to the right frontal lobe were unable to identify an ending to a story that turned it in to a joke. While these patients had normal reasoning capacity it seemed that their sense of humor was impaired in some way.


The right frontal lobe is the part of the brain that brings together information from the cognitive parts of the brain with the emotional parts. It is the integration of the emotional with the cognitive that is important in this case.
One other role the brain plays in the experience of laughter is in the release of hormones and neurotransmitters. Laughter has been shown to cause changes in the autonomic nervous system and to alter stress hormones and neurotransmitter levels.

One early suggestion was that a good laugh could prompt the brain to block the manufacture of immune suppressors such as cortisone or speed up the production of immune enhancers such as beta-endorphins.