论文代写：打哈欠的定义和类型
打哈欠是一种自然而然的过程打开的嘴，深吸一口气，然后释放可能是无聊或瞌睡的标志。如上所述，这是一个非自愿的过程，但人类有能力控制它，由于文化和社会的原因。打哈欠是一种心理现象，而人也打哈欠，如果他看人打哈欠或读到它。这就是为什么打哈欠是会传染的（布特纳和斯特拉瑟，2014）。
有不同类型的打哈欠是由科学家们观察到的。第一个是普遍的打哈欠，这在人类和动物都是一样的。这种类型的哈欠与睡眠、饥饿或其他类似的刺激有关。这是说是由大脑的情感部分产生。这是最常见的打哈欠。打哈欠的二类是情绪打哈欠。这一类的打哈欠是在哺乳动物中观察到的，可以帮助他们获得平静后，焦虑或压力。这些都是由古哺乳动物脑产生。在人类中这种打哈欠会带来一种抗压力的效果。这就是为什么大多数运动员打哈欠准备运动之前（Gallup，2011）。第三类打哈欠是会传染的打哈欠。这是一个打哈欠的人，看一看已经打哈欠的人。这说明大脑的特殊功能。许多科学家与同情心的接触。如果大脑的功能成像是在这个时候，它被看到的是相同的脑功能激活时，接触的传染性打哈欠时，激活时，一种情感的同情，感觉大脑。
然而，打哈欠是无聊和乏味联系。这是一个普遍的认识，如果一个人无聊或是坐着无所事事的很长一段时间，他或她会打哈欠。
论文代写：打哈欠的定义和类型
Yawn is defined as an involuntary process to open the mouth widely, take a deep breath and then release which could be the sign of boredom or lethargies. As mentioned, it is an involuntary process but human beings have got an ability to control it due to cultural and societal reasons. Yawning is a psychological phenomenon due to which a person also yawns if he looks at someone yawning or reads about it. This is the reason why yawning is considered as contagious (Buttner & Strasser, 2014).
There are different types of yawns which are observed by the scientists. The first one is universal yawning which is observed in all i.e. in human beings as well as animals. This type of yawn is connected with sleep, hunger or other such stimuli. These are said to be produced by the emotionless part of the brain. It is the most common type of yawn. The second category of yawn is of emotional yawning. This category of yawning is observed in mammals and can help them to get calm after anxiety or stress. These are produced by paleomammalian brain. In human beings this kind of yawning brings in an anti- stress effect. This is the reason why mostly athletes yawn before going for the sport (Gallup, 2011). The third category of yawning is contagious yawning. This yawn is caused by looking at someone who is already yawning. This shows a special feature of brain. Many scientists relate contagious with empathy. If functional imaging of the brain is done at this time it is seen that the same brain functions activate at the time of contagious yawning as that activated when an emotion of empathy is felt by the brain.
However, yawning is mostly linked with boredom and dullness. It is a common understanding that if a human being is bored or is sitting idle for a long time he or she tends to yawn.