Humans perceive the shape and color of an object through vision through visible light reaching the retina of the eye, but it can only be properly achieved by the action of the brain. One of the three books of librarianship, the verse of Jeongshimjang of the University, says, “If you don’t have a heart, you can’t see it, see it, hear it, you can’t hear it, and you don’t know its taste when you eat it.” Comes out. It is the old Sunghyun’s teaching that emphasizes the very importance of cultivating the mind correctly, but it is a very accurate expression even from the perspective of brain science and cognitive science today.
A few years ago, a picture of a dress by a rural woman in England was disagreeed with what color it was, and there was a tumultuous debate around the world. In other words, a young woman named Caitlin McNeil, who was active as a singer of a traditional Scottish music band, posted an image of a plain dress with lace on her SNS. As a result, some people perceived it differently as’golden lace on a white background’.
Tens of millions of netizens around the world participated in this dress color debate, causing fierce quarrels and confusion, and later, fashion officials, photography and opticians, and cognitive scientists also added to explain why they look different depending on the person. . The dress in question was originally a blue background with black lace, but why did so many people perceive it as a white background with gold lace?
As a result of experimenting with a visual psychologist wearing the same dress as that of a Scottish woman singer, it is said that the same dress was viewed differently in blue-black or white-gold depending on the person. In addition, even with the same person, as a result of trying different lighting to illuminate the dress, the same dress was recognized as a different color.
Viewing the same dress differently from person to person or light to light has a deep connection to so-called color constancy. The color of an object reflects a specific wavelength of sunlight or lighting, more precisely, by absorbing a wavelength band of complementary colors, but sunlight and lighting are not always the same and change over time and conditions. For example, sunlight shining in the middle of the day and morning or evening cannot be the same, and when there is a cloud, it changes a little, and our brain uses a method called color homeostasis to correct for the light that changes from moment to moment.
For example, even if it is a red apple, the wavelength band of the light reflected there will be slightly different, but the human eye perceives that the apple is red, whether it is in the sunny or indoors, at noon or at sunset. If there is no color homeostasis, apples viewed under sunlight should have a slightly bluish tint than indoors, and apples viewed at sunset should appear more orange.
However, human color homeostasis cannot be perfect, and in particular, it is difficult to determine exactly what color the lighting is, so something like a dress color debate takes place. In other words, assuming that blue was included in the lighting without their knowledge, those who saw the dress perceived it as white and gold, and those who thought that the lighting would be close to natural light or yellow perceived the dress as blue and black.
The dress color debate dramatically showed that it is the brain rather than the human eye that ultimately determines the visible color, and it is not a few cases where the brain makes mistakes by the memory color. Memory color refers to a color recognized as a stereotype in a person’s head through memories of the past. For example, the memory color of apples is red, bananas are yellow, and bushes and grass are green.
A neuroscientist once did an experiment on memory color, and under red light, subjects were shown a banana-shaped object with a white card and asked what color it was. The subjects replied that the banana-shaped object was yellow, but when the general light was turned on, the banana-shaped object was revealed to be white, just like the color of the card, and the subjects burst into laughter with absurdity.
Bananas are the ones that most subjects misunderstood by the memory color of yellow, and the less visual-related information is provided, the more people are dependent on the memory color. In other words, under extreme red lighting, the brain receives much less information than normal white lighting, which leads to false judgments.
In addition to memory color, there are many examples that prove that the brain’s action is crucial for color recognition, and for example, differences in language and culture according to race and ethnicity also affect color perception.