Perceptual organization: To reverse back the inverted (upside-down) question of feature binding

In addressing the most fundamental question of "Where visual processing begins", all theories of perception can be segregated into two contrasting lines of thinking: "early feature-analysis" (i.e., from local to global processing) and "early holistic registration" (i.e., from global to local processing). The problem of feature binding is then essentially a consequence of the particular local-to-global assumption. However, from the global-to-local perspective, the problem of feature binding may be a wrong question to ask to begin with, while the Gestalt concept of perceptual organization serves to reverse this inverted position. Inspired by the analysis of invariants over transformations, particularly shape-changing transformations, a topological approach has been proposed to describe precisely the nature and rules of perceptual organization. Evidence supporting topological perception will be illustrated in topics of visual sensitivity, apparent motion, illusory conjunctions, and the relative salience of different geometric invariants.