A Non-Modular Approach to Visual Space Perception. Issue 2 (3rd April 2017) - Sedgwick, H. A.
ABSTRACT: In the first part of this article, we outline Rene Descartes' (1637/1965) list of cues for perceiving distance. We show that this list has essentially persisted up to the present. What began, however, as a heterogeneous list of ways of perceiving distance was reified by David Marr into a set of modular processes instantiated in the visual system. We suggest that this modular approach does not conform well to what is now known about visual space perception. We show that Marr, although strongly influenced by Gibson, did not adopt the view of visual space perception developed in The Senses Considered as Perceptual Systems (Gibson, 1966). In the second part of this article, we show that there is considerable non-modular structure in the optic array that is used to perceive spatial layout. We describe, with examples from the literature, 5 major forms of structure, all of which cut across different forms of information pickup. These are (a) surfaces as references, (b) local and non-local processing, (c) compression and shear, (d) analogous geometrical structures, and (e) boundaries and surfaces.