Historically, the visual system has been classified into two subsystems, the so called ventral stream for shape recognition and the dorsal stream for spatial localization. Because the primary importance of 3D structure is define spatial layout, one might expect that depth perception recruits mainly brain areas in the dorsal stream. However, the cortical network of stereoscopic depth perception (based on binocular disparity) in non-human primates, recruits almost every region of the visual cortex including several regions of the temporal lobe.