Realism: an Obstacle to Appreciating the Nature of Visual Space Perception

Naïve realism is the commonsense view that the world we encounter in everyday life is one and the same as the physical world. An opposing view is provided by the philosophy of mind and the scientific study of percep-tion—contact with the physical world is mediate, and what we experience in everyday life is a representation created by our senses and central nervous system (1-3). Indeed, this representation (usually referred to as the perceptual or phenomenal world), being a product of sensory and neural processes that have been perfected by millions of years of evolution, is so highly consistent and veridical that we are able to routinely make life-depending decisions (as in driving) without ever suspecting that the perceptual information upon which we are relying is once removed from the physical world. In fact, it is precisely because the perceptual process is so highly functional that we fail to recognize its very existence. It is for this reason that the layperson thinks of perception as little more than attending to aspects of the environment and that many erudite people, including many scientists, fail to appreciate the scope and magnitude of perception as an intellectual problem. There is hardly a topic in perception that is more difficult to appreciate as an intellectual problem than visual space perception, especially in connection with natural large-scale environments. In order for us to properly grasp the nature of perception, we need to eliminate naïve realism from our thinking as much as possible. Geometric visual illusions and other visual phenomena, like diplopic vision, binocular stereopsis elicited by stereo-grams, and perceived 3-D shape from motion, do help expunge naïve realism from our thinking by providing examples of how perception can deviate from physical reality. However, such circumscribed visual phenomena tend to exert only local influences on our thinking rather than inducing a global restructuring of our conceptions of perceptual experience. Thus, even though these visual phenomena make us recognize the fallacy of naïve Visual space perception: phenomenology and function ABSTRACT This article presents a brief overview of visual space perception. It begins by noting the significance of visual space perception to broader issues in philosophy and science and observes that the appreciation of visual space perception as a scientific topic is impeded by naïve realism. The second section notes the longstanding interest in the phenomenology of visual space and focuses on one issue, the dissocation between perceived location …