Why does our brain stubbornly impose on us an erroneous picture of the world, even if we know how things are in reality? How do illusions appear and what are their benefits and harms?
A long time ago, philosophers were interested in how much what we perceive corresponds to how the world really is. For example, the ancient Greek philosopher Democritus believed that thin shells are separated from the things that surround us. They fly and hit the retina of the eye, and an exact imprint is obtained there.
About the same thought many centuries later, Rene Descartes. But even the simplest experiments show that this imprint is incomplete and can correspond to anything. In fact, what we see is determined not only by the eyes, but also by the brain.
From mistakes to mechanisms
Back in the XNUMXth-XNUMXth centuries, pictures began to appear that showed that the same thing can be perceived in different ways. This was actively pursued by magicians and illusionists, who were the first to discover that our attention can be controlled.
At the beginning of the XNUMXst century, a whole direction was announced – neuromagic. She suggested moving from ambiguities, mistakes, illusions of our perception to the mechanisms behind them.
Scientists have created a whole classification of what can generate errors in our perception. They can be associated with attention, memory, the work of thinking – in fact, with all cognitive processes. And it turns out that they can be influenced very strongly.
Perception or image building is a very efficient process. It works in a fraction of a second and allows you to very accurately grasp the meaning of any, even very difficult situation. Due to the fact that our perception is sharpened for a very wide range of tasks (recognition of objects, people and their actions, including in unusual situations), such a quick grasp can produce errors.
These perceptual errors – illusions – have proven to be a good clue to understanding how perception works.
Illusion is defined very simply: as a distortion in the perception of any attribute of an object – shape, name, position in space. All of these features are very context dependent.
For example, the brightness of an object or its color is not perceived by itself, but is set by the context in which we see this object. The now-famous dress illusion, seen by some users as black and blue and others as white and gold, has to do with how the brain interprets the light source and the strength of the light.
And if the object is moving, we see not its current position in space, but the position in which it will be in a fraction of a second. Evolution has endowed our visual system with the ability to predict the future. It was probably necessary for survival.
And there are illusions that are absolutely and completely determined by our experience and knowledge about the world.
Under the dictates of the brain
If we look at how the process of perception works, we will see that these are always two opposite streams – ascending and descending.
- ascending includes external influence – information about color, light and shape that enters the retina and is transmitted to the next levels of information analysis.
- Descending determined by what they want from us, that we know in what context this information is presented. And it is only as a result of the interaction of these flows that we get what we will eventually see.
The idea that the ascending line is more important appeared a very long time ago, in the XNUMXth century, in the works of the physicist and physiologist Hermann Helmholtz, who came up with the theory of unconscious inferences.
He believed that perception is arranged by analogy with thinking, that is, it is rather a conclusion
We have some small premise: what is affecting us now. We juxtapose this impact with the big premise—all of our past experiences. Therefore, if we perceive something differently than it is, in fact, this is an error of inference.
The main source of illusions is our knowledge of the world. Therefore, our perception is characterized by the so-called objectivity. This means that we do not perceive colors, shapes or angles. We perceive objects. If we look at a face, we see not a set of lines and areas of different brightness, but a face.
When external influences and our knowledge come into conflict, our experience in most cases turns out to be overwhelming, and conflicts do not arise. For example, let’s take the same face. It is not concave. Therefore, if we are shown a rotating mask, we see it convex from one side and the other.
I see because I want
Perception is determined not only by our experience, but also by our willingness to define the situation in this way and not otherwise, that is, our attitudes. These attitudes, in turn, can be set by the context (we were shown a familiar form, and we are ready to see what we expect to see), our desires and experiences.
For example, the proverb “Fear has big eyes” says exactly this: something frightening will seem larger than it really is. The same applies to objects that are attractive to us.
One of the founders of cognitive psychology, Jerome Bruner, conducted experiments with perception in the 1940s. He compared how children evaluate the size of cardboard circles and the size of coins. For any child, a coin is more important than a piece of cardboard.
We will see that compared to the values of the circles, the coins are significantly overvalued.
Moreover, it all depends on what environment the child comes from. Bruner specifically took children from wealthy families who have pocket money and children from poor families who do not.
Poor kids overvalue coins more than rich kids. And here’s the interesting thing: they overvalue the dime more than the twenty cent. Perhaps because they simply did not see such money.
About expert
Maria Falikman — Candidate of Sciences in Psychology, Senior Researcher at the Center for Cognitive Research at the Faculty of Philology of Moscow State University, Leading Researcher at the Faculty of Psychology at Moscow State University, Leading Researcher at the Laboratory for Cognitive Research at the National Research University Higher School of Economics.