reason, why yawning can be contagious

Yawning is a reflex action that occurs at all, is usually done to breathe the air in large quantities and followed by breathing. The reflex action is often associated with stress, fatigue, too much work, boredom and sleepiness. Yawning can also occur when there is excess carbon dioxide or a shortage of oxygen in the bloodstream.

Recent studies have shown yawning as a sign of someone not only wants to sleep. But the purpose evaporates to cool the brain so it can operate more efficiently and make someone stay awake.

But why when someone who saw it evaporate also evaporate?

"We think the cause is contagious yawning is triggered by empathic mechanisms which function to maintain group vigilance. Therefore yawning a sign of empathy," said researcher Dr Gordon Gallup, as quoted by BBC News, Thursday .

Another cause of contagious yawning in the nervous system active mirror (mirror neurons system) neurons are located at the front of each hemisphere of the brain certain vertebrates.

When receiving a stimulus (stimulus) of the same species, then the species will also activate the same regions in the brain. This is why a person will yawn if they see another oang evaporate.

The nervous system acts as a mirror drive to replicate and be responsible for human learning. Therefore yawning is often regarded as a branch of the impulse (movement) of the same clone.

If the center of the mirror neuron system is not active when seeing someone yawn, then it will not have a relationship with the desire to respond to evaporate.

The stronger a person wants to evaporate, the stronger activation of the brain periamygdalar left. This finding is the first to reveal the neurophysiological signs that yawning can be contagious.

Periamygdalar region is a zone that is located next to the amygdala and almond shaped structure located deep in the brain.

Activation of some of the chemicals found in the brain, eg, serotonin, dopamine, glutamine, glutamic acid and nitric oxide, may also increase the frequency of yawning. While some chemicals such as endorphins can actually reduce the frequency of yawning.

If someone yawn, then there are steps that occur are:

• Starting with an open mouth
• Jaw moves down
• Maximize air may be drawn into the lungs
• Inhaling air
• Abdominal muscles to contract
• The diaphragm is driven down the lung
• Recently some air is blown back.

Several studies have shown the benefits of yawning is to stabilize the pressure on both sides of the eardrum or similar to stretching, flexing muscles and joints in the body and increase blood pressure and heart rate.

Easier Yawning Contagious Among Family Members or Friends, Instead of the Unknown People.

Recent findings reveal that social empathy has an important role here. The scientists found that contagious yawning depends on whether or not a strong bond between the people who are in such a place. Family members are the most likely to trigger contagion evaporated, followed by friends, then strangers or new unknown.

Researchers from Italy, as quoted by the Huffington Post page edition of December 8, 2011, spent a year to record the evaporation of 109 adults - 53 men and 56 women - from around the world. Participants were divided into categories of 'triggers' that first yawn and 'observers' who responded with a yawn.

Overall, there were 480 instances in which a person yawning can trigger others nearby to evaporate within three minutes. The conclusion of the article written in the online journal Public Library of Science ONE, according to author Dr. Ivan Norscia and Dr Elisabeta Palagi of the University of Pisa, "Family members are the biggest triggers yawning, both the occurrence and frequency of occurrence."