Saturday, November 3, 2012
ඉතිං එන්න, යාළුවනේ, මේ සයිට් එකේ පිටු අතරේ සැරි සරමින් ඇති තරම් විනෝද වෙන්න.
Tuesday, August 24, 2010
Laughter is an audible expression or the appearance of happiness, or an inward feeling of joy (laughing on the inside). It may ensue (as a physiological reaction) from jokes, tickling or other stimuli. It is in most cases a very pleasant sensation.
Laughter is found among various animals, as well as in humans. Among the human species, it is a part of human behavior regulated by the brain, helping humans clarify their intentions in social interaction and providing an emotional context to conversations. Laughter is used as a signal for being part of a group — it signals acceptance and positive interactions with others. Laughter is sometimes seemingly contagious, and the laughter of one person can itself provoke laughter from others as a positive feedback. This may account in part for the popularity of laugh tracks insituation comedy television shows.
Laughter is anatomically caused by the epiglottis constricting the larynx. The study of humor and laughter, and its psychological and physiological effects on the human body, is called gel otology.
A positive link between laughter and healthy function of blood vessels was first reported in 2005 by researchers at the University of Maryland Medical Center with laughter causing the inner lining of blood vessels, the endothelium, to dilate or expand such to increase blood flow. Drs. Michael Miller (University of Maryland) and William Fry (Stanford), theorize that beta-endorphin like compounds released by the hypothalamus activate receptors on the endothelial surface to release nitric oxide, thereby resulting in dilation of vessels. Other cardio protective properties of nitric oxide include reduction of inflammation and decreased platelet aggregation. The association between laughter and endothelial dilation was recently confirmed by other investigators.
A general theory that explains laughter is called the relief theory. Sigmund Freud summarized it in his theory that laughter releases tension and "psychic energy". This theory is one of the justifications of the beliefs that laughter is beneficial for one's health. This theory explains why laughter can be as a coping mechanism for when one is upset, angry or sad.
Philosopher John Morreall theorizes that human laughter may have its biological origins as a kind of shared expression of relief at the passing of danger. Friedrich Nietzsche, by contrast, suggested laughter to be a reaction to the sense of existential loneliness and mortality that only humans feel.
For example, this is how this theory works in the case of humor: a joke creates an inconsistency, the sentence appears to be not relevant, and we automatically try to understand what the sentence says, supposes, doesn't say, and implies; if we are successful in solving this 'cognitiveriddle', and we find out what is hidden within the sentence, and what is the underlying thought, and we bring foreground what was in the background, and we realize that the surprise wasn't dangerous, we eventually laugh with relief. Otherwise, if the inconsistency is not resolved, there is no laugh, as Mack Sennett pointed out: "when the audience is confused, it doesn't laugh" (this is the one of the basic laws of a comedian, called "exactness"). It is important to note that the inconsistency may be resolved, and there may still be no laugh. Due to the fact that laughter is a social mechanism, we may not feel like we are in danger, however, the physical act of laughing may not take place. In addition, the extent of the inconsistency (timing, rhythm, etc.) has to do with the amount of danger we feel, and thus how hard or long we laugh. This explanation is also confirmed by modern neurophysiology (see section Laughter and the brain).
Laughter can also be brought on by tickling. Although it is found unpleasant by most people, being tickled often causes heavy laughter which is thought to be a reflex of the body, and is often uncontrollable.
It has also been shown that laughter is highly contagious, as shown in one case where schools in an area were closed for six months as a result of a massive laughter epidemic.