Figure 10. Otsu segmentation of the real (left) and the impossible (inverted) figure (right)

This regularity of cognition is about the geometry of the internal representation of the
external world, which somehow most often is approximating the Euclidean space according to L.M.
Vekker (1976). In his theory of the Gestalt in perception and thinking, Vekker postulated that
sensations, perceptions and imagination are in a constant process of unfolding to match and take the
exact places of the physical objects in the external environment. The geometry of the internal
representation of the world is abstract and experiential at the same time. The experiential aspect of
the process of immediate cognition can be seen by viewing figure 9. Figure 9 right is, at first glance,
a quite convincing example of stairs similar to the stairs on the left. Even the context (the cat on the
ceiling) is noticed on a second scan. The inverted stairs are more likely to remind us of Escher’s
works than, for example, the normally positioned ones. This effect supports the idea of the semantic
depth of spatial learning, relating the experience of art to perceiving of Gestalts.