Illusion and Reality

It is possible in the framework of embodied and inacted approach to cognition to suggest a new solution of some problems that have been discussed in philosophy and psychology for a lot of time.

One of them is the problem of the relations between illusion and reality. It seems that the content of perception is the same independently of the fact that one per­ceives what really exists or has an illusion. Because it was a common opinion that only this content is directly given to a perceiver, one could think that it is impos­sible to be certain whether perception refers to a real situation. It seemed that psychological experiments (for example, “a room of Ames”) support this opinion. And in the case of a “gestal-switch” (a rabbit or a duck) it is senseless to speak about a distinction between illusion and reality.

But perception is actually not a static state of consciousness, but a process of extracting information, carried out in actions of a cognizing agent with the aim of inspecting a real situation. So it is impossible to understand, for example, the nature of visual perception by studying the perception of a drawing—as it was made by several generations of psychologists who proceeded from the idea that the brain interprets a picture on the eye's retina (the latter exists in 2 dimensions, so it seems similar to a picture) in the same way as a human being sees a drawing. But real perception can be understood if a researcher starts from studying the perception of real situations with which a human being or other cognizing being deal, and only after that studies perception of drawing, pictures, schemes, paintings and other artificial representations.

Illusions happen in real life. They are not inventions of consciousness, but are conditioned by real situations of perceiving. For example, a spoon in a glass of water seems to be broken.

In the case of “Ames room” a psychologist creates an artificial situation, when an observation of the interior of a room is made from a single point of view and through a narrow hole: the observer cannot see the interior from another point of view (because she/he is not permitted to move), cannot make the hole wider. In other words, an observer is under such conditions, when she/he can do only one thing: to stay in the same place and passively see a scene inside a room. As soon as the observer is allowed to move and to see the interior from another point of view, the illusion disappears.

Perceiving presupposes active examination of a situation with the help of actions. They are not chaotic, but are carried out with the help of a scheme, which determines a way of examining and is formed as result of former interactions of a cognizing agent with surroundings (Neisser 1976). A scheme is not such a mental representation that exists between a cognizing agent and realty and blocks getting reality and is the only present to an agent. A scheme really is a mode of an interaction of a cognizing being with the real world for extracting information (sometimes these schemes are called “activity oriented representations”). A scheme determines a certain “horizon of expectations”.

Here is an example. A person regularly goes from home to a subway station passing near a certain house. One day she/he walked near this house and recognized it. But when she/he went round it, realized that the house didn't exist any more: there was only one wall of the former house left. The wall was illusionary perceived by that person as a whole house. It turned out that at night the house was destroyed in order to build a new one at that place. So the first perception was an illusion. But as there was a possibility to continue moving and to go around the wall the illusion disappeared.

One cannot examine drawings and other pictures as it is possible in relation to real objects and situations. So one cannot distinguish illusion and reality in such situations, to decide, for example, what exists: a rabbit or a duck. One cannot get rid of an illusory perception of two sections on a paper as unequal, although she/he knows very well that they are really equal (the famous Muller-Lyer illusion). But in real life one never mixes a rabbit and a duck and never makes a mistake concerning dimensions of two real sticks which she/he is manipulating.

So the mental content of an adequate and of an illusory perception is not the same— in distinction from how it was understood in traditional philosophy and psychology. Because the content of perception is not a certain static ideal entity, but information that is extracted from a real situation by a process of active examination. If there are no obstacles for such examination, perception is adequate, if such obstacles exist or if such examination is impossible in principle (as it is, for example, in cases of draw­ings), then illusions are possible and sometimes can be very stable.

It is impossible also to examine those situations that are presented in dreaming and hallucinations. “A test for reality” doesn't work in such cases. Meanwhile a lot has been written about the supposed impossibility to distinguish a content of dreaming and hallucinations from a content of adequate perceptions (an idea of “a world as dreaming”).

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