Organizing the observation and perception process - background and figure
The second element is the background and figure. Each object is seen in the context of its surroundings or background, due to the tendency to see things as a whole. The evaluation of the item’s size may be wrong, resulting from incorrect interpretation of the background. A classic example is the Köhler cross or the “impossible staircase” illusion. Background or surroundings refer not only to colour or things, but also previous experiences. About 90% of everyday sensory experiences are perceived by the humans in a habitual way based on what they have experienced so far. For example, a small white spot at the end of the lake is perceived as a boat, without actually checking this fact, which may lead to illusions.
Does the above figure show a red triangle on a black rhombus or a black triangle on a red rhombus? Or maybe two triangles?
In some cases, it is difficult to distinguish a background from a figure – as is the case with the famous illusion drawing “two faces and a cup”.