In a world where most people are right-handed, lefties are destined to attract attention. There are various opinions about left-handed: some people say that left-handed people are smarter and left-handed people are more affectionate; Some people think that being left-handed is a bit silly, and even think that being left-handed is an abnormal physiological phenomenon. When left-handed people keep appearing around us, even when you are left-handed, the question will suddenly arise: Are these statements reasonable? What are the reasons for being left-handed? Chen Yuedong, deputy chief physician of the Department of Orthopaedics, Nanjing 454 Hospital, is left-handed. As a surgeon, can being left-handed affect the operation? When the reporter learned that he was left-handed, he immediately thought of this problem. "I used to use my left hand since I was a child. I use chopsticks as my left hand when I eat. At first, writing with a pen was also my left hand. When doing things, others are convenient for the right hand and I am convenient for the left hand. " Chen Yuedong smiled when he mentioned that he was left-handed, and the family got together for dinner. Because he uses chopsticks in his left hand and others hold chopsticks in his right hand, chopsticks often "fight". After attending a medical university, especially after starting an internship, Chen Yuedong found that being left-handed can bring a lot of trouble to a surgeon. "Many medical devices, such as pliers, tweezers, scissors, etc. Most of them are designed and manufactured according to the habit of using the right hand. For left-handers, using these medical devices is sometimes very inconvenient. " Chen Yuedong said. "In surgical operations such as laparotomy, the surgeon is basically standing on the right side of the patient, holding a scalpel in his right hand and assisting with his left hand, which is very convenient. If you are left-handed, it is very clumsy to hold a scalpel in your left hand and assist the operation with your right hand. Because the operation is the cooperation between the main knife and the assistant, the right-handed knife and the left-handed pliers or tweezers, if the left-handed knife is used by the left-handed, it is easy to be accidentally injured because of the mindset, and the consequences are very serious. " Chen Yuedong said: "To be a good surgeon, you can't rely on your left hand. You must practice your right hand. During my internship, I began to practice my right hand deliberately, peeling apples with my right hand and cutting vegetables with my right hand ... A few years later, my right hand was as flexible as my left hand. " Today, Chen Yuedong is already a "left and right" surgeon. Being left-handed also gives him an advantage over other doctors in the operation. When sewing and knotting, his left and right hands can do it. During the operation, he used his left hand and right hand alternately, as if he were performing. Left-handed people have a special right brain. Many people have this question: Why are some people used to using their left hands? Why do left-handers still exist, although they are a minority? Dr. Xie Shiping, director of psychiatry department of Nanjing Brain Hospital, said that some people will get used to using their left hand, which is related to the theory of hemispheric dominance. The brain is divided into left hemisphere and right hemisphere. The left hemisphere is responsible for all activities on a person's right side. Generally, the left hemisphere has the functions of language, concepts, numbers, analysis and logical reasoning, and belongs to the "rational hemisphere". The right brain is responsible for all activities of the left brain. The right brain has the functions of music, painting, space geometry, imagination and synthesis, and belongs to the "artistic hemisphere". If a person's left brain is dominant, he usually uses his right hand, which is right-handed; If the right brain is dominant, it is generally left-handed, that is, left-handed Of course, which side of the brain is dominant and which hand is often used is largely determined by genetic factors. In recent years, it has been found that when both parents are left-handed, the proportion of left-handed children is 46%. In further research, scientists found that the characteristics of left-handed people originated from the brain structure. Different from ordinary animals, the human brain not only has the function of directly or indirectly regulating the physiological activities of various organs and systems of the body, but also becomes an organ of thinking and language, enabling human beings to transcend the category of ordinary animals and form a society in productive labor. The wonder of the human brain lies in the different division of labor between the two hemispheres. The left hemisphere dominates the activities of the right hemisphere, and the right hemisphere dominates the activities of the left hemisphere. The two hemispheres of the brain are connected by the corpus callosum, that is, transverse nerve fibers connecting the two hemispheres. The corpus callosum is responsible for the transmission of nerve information between the two hemispheres of the brain. The corpus callosum of left-handed people is more developed. The deviation of human body movements will naturally stimulate the development of the corresponding hemisphere of the brain and have a significant impact on human ability. Left-handed people often use their left limbs, and the right hemisphere receives relatively more stimulation, which makes left-handed people tend to think in the brain. Therefore, relatively speaking, left-handed people may have stronger perception, sense of space and ability to grasp the overall situation.
Why left-handed athletes often lead more than a century ago, some people thought that left-handed athletes were an abnormal physiological phenomenon and regarded them as a disease. They think this is because the left brain of the baby is damaged when the mother encounters dystocia, so that the baby often uses his left hand in the later growth process. Therefore, all left-handers are often accompanied by stuttering and mental retardation. But it turns out that this is not entirely the case. It is found that many left-handers around us are not only stuttering and mentally retarded, on the contrary, they are very talented. Are lefties smarter? Dr. Xie Shiping believes that there is no scientific evidence that "left-handed people are smarter". Many people have made a comparative study on the IQ of left-handed and right-handed people and found that there is no significant difference between them. Besides left-handed celebrities, more celebrities are right-handed. Left-handers' well-developed corpus callosum makes them more agile, which is fully reflected in many excellent left-handers and forms a saying that left-handers are smarter in society. This can be seen clearly in the sports field. Generally speaking, for sports that don't need face-to-face fighting, such as swimming, track and field, shooting, etc. The proportion of left-handed athletes is not high compared with their proportion in the population. However, for those face-to-face fighting events that bring players closer in the competition, such as fencing, table tennis and basketball, the proportion of left-handed athletes in the population is much higher than that of left-handed athletes. In fencing, the most typical fighting event, between 1979 and 1993, half of the male players reached the quarterfinals of the World Championships, and one third of the female players were left-handed. Table tennis has been dominated by lefties for many years, tennis has been dominated by lefties for a long time, and NBA professional basketball in the United States is also left-handed.