The human visual system is able to combine different visual inputs in the two eyes and to fuse them, creating the appearance of a single cyclopean image. To understand binocular vision, then, it is crucial to understand the nature of this process of binocular combination. This has been addressed by systematically varying the difference between the monocular inputs. Several types of image difference have been studied, including local phase (Ding & Sperling,
2006; Huang, Zhou, Lu, Feng, & Zhou,
2009; Zhou, Jia, Huang, & Hess,
2013), luminance contrast (D. H. Baker, Wallis, Georgeson, & Meese,
2012a; Ding, Klein, & Levi,
2013a,
2013b; Huang, Zhou, Lu, & Zhou,
2011; Huang, Zhou, Zhou, & Lu,
2010; Legge,
1984a,
1984b), stereo disparity (Hou, Huang, Liang, Zhou, & Lu,
2013; Legge & Gu,
1989; Reynaud, Zhou, & Hess,
2013), global motion (Hess, Hutchinson, Ledgeway, & Mansouri,
2007; Mansouri, Thompson, & Hess,
2008), and global orientation (Zhou, Huang, & Hess,
2013). Different models have been constructed for binocular combination involving these different kinds of visual information. One common feature of these models is the need for an interocular contrast-gain control weighting stage (Ding et al.,
2013a,
2013b; Ding & Sperling,
2006; Hou et al.,
2013; Huang et al.,
2009; Huang et al.,
2011; Huang et al.,
2010; Meese, Georgeson, & Baker,
2005,
2006; Meese & Hess,
2004; Meese & Summers,
2009).