A SERIOUS LOOK AT LAUGHTER

Laughter is very complicated, although few people know this fact. Laughter is the physiological response to humor. Laughter consists of two parts -- a set of gestures and the production of a sound. When we laugh, the brain pressures us to conduct both those activities simultaneously. When we laugh heartily, changes occur in many parts of the body, even the arms, legs and trunk muscles. Fifteen facial muscles contract and stimulation of the zygomatic major muscle (the main lifting mechanism of your upper lip) occurs. Meanwhile, the respiratory system is upset by the epiglottis half-closing the larynx, so that air intake occurs irregularly, making you gasp. In extreme circumstances, the tear ducts are activated, so that while the mouth is opening and closing and the struggle for oxygen intake continues, the face becomes moist and often red (or in extreme cases purple).

Noted humor researcher Peter Derks describes laughter response as "a really quick, automatic type of behavior." The physiological study of laughter has its own name -- gelotology. And we know that certain parts of the brain are responsible for certain human functions. Researchers have learned that the production of laughter is involved with various regions of the brain. While the relationship between laughter and the brain is not fully understood, researchers are making some progress. For example, Derks traced the pattern of brainwave activity in subjects responding to humorous material. Subjects were hooked up to an electroencephalograph (EEG) and their brain activity was measured when they laughed. In each case, the brain produced a regular electrical pattern. Within four-tenths of a second of exposure to something potentially funny, an electrical wave moved through the cerebral cortex, the largest part of the brain. If the wave took a negative charge, laughter resulted. If it maintained a positive charge, no response was given, researchers said. During the experiment, researchers observed the following specific activities: The left side of the cortex (the layer of cells that covers the entire surface of the forebrain) analyzed the words and structure of the joke. The brain's large frontal lobe, which is involved in social emotional responses, became very active. The right hemisphere of the cortex carried out the intellectual analysis required to "get" the joke. Brainwave activity then spread to the sensory processing area of the occipital lobe (the area on the back of the head that contains the cells that process visual signals).

We laugh 30 times as much when we’re with other people as we do when we’re alone. The purpose of a laugh could be to trigger positive feelings in other people. We’ve evolved to be that way. Our Sense of Humor Doesn't Fade with Age either. We’ve all heard the claim that laughter is the best medicine. But according to many media reports laughter is a panacea that will heal your immune system, dull your pain, improve your memory, lower blood pressure, and perform other wondrous feats.