The SPIN theory--a navigational approach to space perception

A fundamental problem in the study of spatial orientation concerns how a mobile observer navigates in space on the basis of retinal and extraretinal signals while obtaining the perceptual constancies of position size and shape across head and eye movements. This problem was dealt with by the inferential, direct perception, and computational approaches, yet it is not fully understood. In theory, the above constancies could be obtained from retinal information if the absolute distance is known. However, the common view is that the problem can be determined only up to a scalar in the velocity vector, providing only relative depth. This paper is a theoretical one. It elaborates on an original mathematical theory for space perception (SPIN theory) which suggests that mental representation of objects is exocentric rather than egocentric. The theory postulates absolute (metric) depth perception and shows its mathematical feasibility. It regards space perception as a navigational process that combines retinal and extraretinal signals in a manner that enables continuous phenomenological experience of time invariant (exocentric) representation across fixations and saccades. The theory considers the Listing and Donders' laws of eye movement, as well as the vestibulo-ocular reflex, and suggests some newly driven theological conjectures for them.