Since submitting this paper I have found an elegant paper by Taya et al (1995) where they arrive at the same theoretical conclusion, and provide psychophysical evidence for it. However the broader point is not that I necessarily subscribe to this particular perceptual interpretation, but rather that if this explanation were accepted, then the observed field-like propagation of the perceptual properties would best be described by a field-like model. That the theoretical interpretation of Taya et al. would be expressed in an isomorphic model exactly as it is perceived. This particular problem in perception is being used as an example of how the proposed general principles would be implemented to describe a particular phenomenon. A different phenomenal description would require a different isomorphic model. The point is that it would never occur to most neural modelers to express a field-like percept with a field-like computational mechanism, which is not available in their conceptual tool-box of ideas.