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Illustration of the interplay between border ownership assignment and transparency detection. The same edge (identified by an identical luminance difference throughout) is perceived as (A) part of the contour of the small square, (B) part of a black vertical bar that lies underneath a transparent horizontal bar, (C) again part of the contour of the small square. Source: From Qiu and von der Heydt (2007). Copyright 2007 Nature Publishing Group; reprinted by permission.
