When people need even more proof of reality than via the naked eye, they intuitively try to touch the to-be-analyzed entity (if at all possible) in order to investigate it haptically. The assumed link between perception and physical reality is particularly strong for the visual sense-in fact, we scrutinize it only when sight conditions have been unfortunate, when people have bad vision or when we know that the eyewitness was under stress or was lacking in cognitive faculties. Indeed, it seems that there is no better, no more “proof” of something being factual knowledge than having perceived it. Most obviously, you can experience this with eyewitness testimonies: If an eyewitness has “seen it with the naked eye”, judges, jury members and attendees take the reports of these percepts not only as strong evidence, but usually as fact-despite the active and biasing processes on basis of perception and memory. Sensory perception is often the most striking proof of something factual-when we perceive something, we interpret it and take it as “objective”, “real”. Gregory (e.g., Gregory, 2009), by discussing specific visual illusions and how they can help us to understand the magic of perception.Ībout the Veridicality of Perception The Relationship Between Reality and Object The present paper strengthens this line of argument, strongly put forth by perceptual pioneer Richard L. The main task of human perception is to amplify and strengthen sensory inputs to be able to perceive, orientate and act very quickly, specifically and efficiently. Illusions in a scientific context are not mainly created to reveal the failures of our perception or the dysfunctions of our apparatus, but instead point to the specific power of human perception. Furthermore, they let us analyze the cognitive sub-processes underlying our perception. It may be fun to perceive illusions, but the understanding of how they work is even more stimulating and sustainable: They can tell us where the limits and capacity of our perceptual apparatus are found-they can specify how the constraints of perception are set. 2Bamberg Graduate School of Affective and Cognitive Sciences (BaGrACS), Bamberg, Germany.1Department of General Psychology and Methodology, University of Bamberg, Bamberg, Germany.The review concludes with a comparison of some of the highlights of our novel, successful approach to the recovery of 3D shape from a 2D image with prior, less successful approaches. Recent elaborations of this model include: (i) the recovery of the shapes of natural objects, including human and animal bodies with limbs in varying positions (ii) providing the model with two input images that allowed it to achieve virtually perfect shape constancy from almost all viewing directions. The model makes no use of depth, surfaces or learning. In the rare recoveries in which errors are observed, the errors made by the model and human subjects are very similar. The model recovers 3D shapes from a single 2D image as well, and sometimes even better, than a human being.

This model uses a simplicity principle consisting of only four a priori constraints representing properties of 3D shapes, primarily their symmetry and volume. Appreciating their importance made it possible to devise a computational model that recovers the 3D shape of an object from only one of its 2D images. The importance of both veridicality and complexity was ignored in most prior research. The ability to see objects as they really are “out there” is derived from the complexity inherent in the 3D object’s shape. This paper reviews recent progress towards understanding 3D shape perception made possible by appreciating the significant role that veridicality and complexity play in the natural visual environment.

Veridical perception definition