Macaque inferior temporal neurons are selective for disparity-defined three-dimensional shapes.

Real-world objects are three-dimensional (3D). Yet, it is unknown whether the neurons of the inferior temporal cortex, which is critical for object recognition, are selective for the 3D shape of objects. We tested for such selectivity by comparing responses to stereo-defined curved 3D shapes derived from identical pairs of monocular images. More than one-third of macaque inferior temporal neurons were selective for 3D shape. In the vast majority of those neurons, this selectivity depended on the global binocular disparity gradient and not on the local disparity. Thus, inferior temporal cortex processes not only two-dimensional but also 3D shape information.