Coding of stimulus invariances by inferior temporal neurons.

Primates are able to recognize a particular object despite major differences in the retinal images of the object. Inferior temporal cortex is suggested to be involved in this invariant object recognition. Neurons of this cortex show shape selectivity and it has been shown that this shape selectivity is relatively invariant for changes in the position and size of the shape. We show that macaque inferior temporal cortical neurons may respond to shapes that are defined by relative motion or by texture differences. The degree of shape selectivity can vary for the different visual cues, but overall shape preference is invariant for shapes defined either by luminance, by relative motion or by texture. Also, we found that shape selective inferior temporal neurons respond to partial occluded shapes and that their shape selectivity is similar with and without the partial occlusion. These results suggest that inferior temporal neurons, as a population, can code for an abstract, stimulus invariant shape or object part.