In human perception, figure-ground segregation suggests that stereoscopic cues are grouped over wide areas of the visual field. For example, two abutting rectangles of equal luminance and size are seen as a uniform surface when presented at the same depth, but appear as two surfaces separated by an illusory contour and a step in depth when presented with different retinal disparities. Here, we describe neurons in the monkey visual cortex that signal such illusory contours and can be selective for certain figure-ground directions that human observers perceive at these contours. The results suggest that these neurons group stereoscopic cues over distances up to 8°. In addition, we compare these results with human perception and show that the mean stimulus parameters required by these neurons also induce optimal percepts of illusory contours in human observers.

This content is only available as a PDF.