A related alternative to the von Holst-Mittelstädt model is the spatial remapping theory of Duhamel and Colby (Duhamel et al. 1992; Colby et al. 1995). The role of saccade efference copy on this theory is to initiate an updating of the eye-relative locations of a small number of attended or otherwise salient objects. When post-saccadic object locations are sufficiently congruent with the updated map, stability is perceived. Single-cell and fMRI studies show that neurons at various stages in the visual-processing hierarchy exploit a copy of the saccade command signal in order to shift their receptive field locations in the direction of an impending eye movement microseconds before its initiation (Merriam &amp; Colby 2005; Merriam et al. 2007). Efference copy indicating an impending saccade 20° to the right, in effect, tells relevant neurons: 