Building a pathway between feelings

All senses are related, and this phenomenon is called "synaesthesia". Boya and Ziqi left behind the eternal masterpiece of high mountains and flowing water. Boya's mind was on the mountains, and Ziqi said, "It is as majestic as Mount Tai." Boya's mind was on the water, and Ziqi said, "It is as vast as the river." This is synaesthesia from hearing to vision. Many people have similar experiences. What is rare is that Boya and Ziqi's synaesthesia is both clear and synchronized, and they are in tune with each other.

Qian Zhongshu described synaesthesia in Guanzibian as follows: "In daily experience, vision, hearing, touch, smell and taste can often be connected or communicated with each other, and the fields of the eyes, ears, tongue, nose and body can be unbounded. Colors seem to have temperature, sounds seem to have images, cold and warm seem to have weight, and smells seem to have texture." He often used synaesthesia in Fortress Besieged: "The sky is full of stars, dense and busy. They are silent, but it seems that the sky is bustling." "After a while, the moon was so round that nothing could stick to it, and so light that nothing could hold it down. It floated out from under the fluffy clouds without any worries. It turned out that one side was not full, like a face that was swollen after being slapped." "Miss Fan seemed to have drawn an invisible circle, surrounding herself and Xin Mei inside, and the conversation was so close that even water could not get in."

The generation of synaesthesia is similar to conditioned reflex. Russian scientist Pavlov proved through experiments that if a dog is always allowed to hear a bell before feeding, then the dog will also secrete saliva even if it only hears the bell without feeding food. This is because the area of ​​the cerebral cortex that senses the bell and the area that senses food stimulation are always excited at the same time. Over time, a neural pathway is established between the two excited foci, and the bell can also cause the same effect as food. Similarly, certain feelings often appear together in daily life: seeing a fire makes you feel warm, and seeing snow makes you feel cold, and pathways are established between the feelings.

The nerve fibers of infants grow very fast, and many new synaptic connections are formed every day, which makes it easy for various senses to be connected. For example, when eating chocolate, you happen to hear the sound of wind chimes, and the taste of chocolate will be associated with the sound of wind chimes. The next time you eat chocolate, you seem to hear the sound of wind chimes again. This kind of synaesthesia with a fixed form but inconsistent with the real environment is called "synesthesia". When infants are babbling, they often say some unrelated words, which may be caused by synesthesia. With age, some synapses formed in infancy are strengthened by the environment and retained, while the rest degenerate, the brain is pruned to be more and more logical, and synesthesia gradually disappears. In other words, we may have been synesthetes, but we slowly lost our synesthesia as we grew older. Only a very small number of people still retain synesthesia as adults.

When Vladimir Nabokov, the author of the novel Lolita, was young, he argued with his mother: should the letter "b" be yellow-brown or orange-red, and should the letter "t" be yellow-green or light blue? Both he and his mother were synesthetes. When he read the newspaper, a large area of ​​colorful colors popped up in front of his eyes. If the "b" printed on the newspaper was sky blue, he would feel very awkward. In the creative process, he was not only a writer capturing words, but also a painter applying colors. The famous physicist Feynman was also a synesthete. He saw "n" as light purple and "x" as dark brown. Letter-color synesthesia and number-color synesthesia are more common synesthesia. In addition, there are music-color synesthesia, vocabulary-taste synesthesia, sound-pattern synesthesia, etc. Everyone's synesthesia characteristics are different, and their respective synesthesia characteristics almost remain unchanged throughout their lives.

In order to test whether the synesthesia phenomenon really exists, psychologists designed a "salience experiment" by scattering six number 2s in a pile of number 5s. Ordinary people will find that there are many "5s" and several "2s" in it. People with number-color synesthesia can see at a glance that the six "2s" form a triangle. In their eyes, the colors of "5" and "2" are different, and the difference is very obvious.

Synesthesia has both advantages and disadvantages. A woman named Christina wanted to be a pianist, but every time she sat in front of the piano and her fingers touched the keys, a strong sense of color would hit her whole body, as if she had been electrocuted, which forced her to give up her dream. Russian journalist Shereshevsky has multiple synesthesia. When he sees the content of the manuscript, he will immediately see the color, smell the smell, and have other related reactions. The mutual reinforcement of the senses gives him an amazing memory. He can recite long lists and still recall all the contents a few years later. This massive memory also brought some distress to Shereshevsky in his later years, because he could not forget a lot of trivial details of life.

Synesthesia is not a superpower, nor is it a disease, it is just a little different. We don't have to care whether we have synesthesia or not, but we can cultivate some synesthesia, which will make us have a more wonderful experience when enjoying music and other art.

(The author is an associate professor at Central China Normal University and a member of the Chinese Society for Neuroscience)