Part segmentation at negative minima has indeed been found to explain a number of phenomena in shape perception (see Singh & Hoffman,
2001, for a review), including the perception of symmetry and repetition (Baylis & Driver,
1994), changes in perceived shape associated with reversals of figure and ground (Driver & Baylis,
1996; Hoffman & Singh,
1997), the perception of transparency (Singh & Hoffman,
1998), the localization of vertex height (Bertamini,
2001), visual search asymmetries (Hulleman, te Winkel, & Boselie,
2000; Wolfe & Bennett,
1997; Xu & Singh,
2002), and differential performance in comparing two probes along a shape's outline (Barenholtz & Feldman,
2003). Additionally, change detection involving complex shapes indicates a heightened sensitivity to concavities (Barenholtz, Cohen, Feldman, & Singh,
2003; Cohen, Barenholtz, Singh, & Feldman,
2005). More recently, we have shown using a segment-identification task (Cohen & Singh,
2004) that observers are substantially better at determining whether or not a given contour segment has been taken from the outline of a given shape if it is segmented at negative minima of curvature, rather than at positive maxima or at inflections.