Why does the human brain have feelings?

In fact, expressions such as like and fear are not the patent of human beings, and may be regarded as an instinctive reaction of creatures, but only human beings have summed up such reactions into a name: "emotion" in Chinese. For example, in Sunflower Facing the Sun, the courtship of animals, the cooperative predation of social animals, and the tiger taking the mountain as the king should all be biological instinct, which shows that there is a certain "feeling" between them: as usual, we have heard of such "feeling" cases as "dolphins saving lives in the water" and "wolf children", so writers will describe them anthropomorphically and taste them in their works. Scientists have explored the human brain and found that the activity in the left hemisphere of the brain is related to the "feeling" shown by people. In the EEG examination, the beta brainwave with the frequency of 14- 100Hz can reflect that the subject is in a state of worry, anger, fear, worry, tension or excitement.