Michael J. Braund

James J. Gibson is one of the best known and perhaps most controversial visual theorists of the twentieth century. Writing in the vein of the American functionalists, and immersed in their profound sense of pragmatism, Gibson sought to establish a more rigorous foundation for the study of vision by reworking its most fundamental concepts. Over the five decades of his distinguished career, Gibson brought new clarity to the old problems of the tradition. He offered an alternative theory of perception - one that could accommodate the experimental insights of contemporary research programs. He characterized this new theory as a version of direct perception in order to distinguish it from the traditional indirect approach of Rene Descartes. On Descartes' account, our perceptual awareness of reality comes through the representations we have formed of it within ourselves. In contrast, Gibson's theory of direct perception states that the environment contains all of the information needed to specify its properties. Hence, perceiving these properties is a matter of detecting the information available in the environment. This theory avoids the difficulty of explaining how the mind organizes holistic perceptions from atomic sensations. In what follows, I will attempt to make good these claims by situating the concept of "structure" at the heart of the ecological program. I will argue that this concept is significant precisely because it allows Gibson to locate the moving, perceiving body at the heart of meaningful perceptual experience; an experience which emerges in the dynamical structures that cross the body and the world.

In his keynote address delivered to The American Society for Esthetics in 1976, James J. Gibson wrote, “Architecture and design do not have a satisfactory theoretical basis.” He then asked, “Can an ecological approach to the psychology of perception and behavior provide it?” (1976, p. 413) We believe that it can, at least in part. In this paper, we expand upon Gibson’s insights into the nature of perceptual experience by applying the concept of “affordances” to the design of architectural objects in general, and to the domain of digital architectural design in particular. On our account, the affordance-concept supplies a useful theoretical basis for conceptualizing the relationship between environments and occupants with respect to the form and behavioral meaning of geometrically constructed layouts. Donald Norman (1988) first introduced affordances to interaction design theorists, as a conceptual tool for predicting how agents will interact with a given product. The extensive body of literature that has since emerged, from human-computer-interaction studies (Ackerman, 1996; Conn, 1995; Moran, 1997; Norman, 1999) to architectural theory and practice (Koutamanis, 2006; Maier and Fadel, 2009), has followed Norman’s lead in defining affordances, somewhat amorphously, as whichever action-related properties of objects are sufficient to elicit the intended forms of behavioral interaction between the agent and object. However, while this is correct, it is only half the story. It leaves unexplained how human perceivers detect and “pair down” on the potentially vast range of possible affordances (at a given time), to select the ones that will be relevant to the coordination and guidance of the targeted actions. Call this the “selectivity problem,” a proper treatment of which is missing from the literature. This is no small matter. If the theory of affordances is to be useful to architects and designers, if it is to have explanatory and predictive power over how perceivers will interact with their surroundings, then some account of the cognitive procedure by which affordances are selected for the deployment of specific behaviors is necessary. Otherwise, it is unclear what the theory hopes to predict or explain. To this end, we maintain that the couching of affordances in a framework of human intentionality is not only consistent with Gibson’s theoretical views (i.e., the action-oriented definition of the concept of affordances not only suggests an intentional perspective), indeed, such a perspective is necessary if we are to succeed in implementing the affordance-concept into an architectural design context in a way that addresses the selectivity problem. This is one of the goals of “Dragonfly,” a first attempt at implementing the affordance-based control of perceptually guided-action into a digital design simulation. Dragonfly enables human interaction with geometry by encoding the basic principles of ecological psychology (including a rudimentary form of intentionality) into an interactive CAD environment. New vistas for future research and interdisciplinary approaches to design are then discussed, with a special emphasis on their applicability to architecture.

The problem of whether perception is direct or if it depends on additional, cognitive contributions made by the perceiving subject, is posed with particular force in an Essay towards a New Theory of Vision. It is evident from the recurrent treatment it receives therein that Berkeley considers it to be one of the central issues concerning perception. Fittingly, the NTV devotes the most attention to it. In this essay, I deal exclusively with Berkeley's treatment of the problem of indirect distance perception, as it is presented in the context of that work.