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

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