Induced effects of backgrounds and foregrounds in three-dimensional configurations: the role of T-junctions.

In three-dimensional configurations, and two-dimensional pictures of such configurations, simultaneous contrast induction from proximate backgrounds affects perceived brightness, color, and internal contrast to a greater extent than induction from coplanar or occluding surrounds or from more distant backgrounds. In the projected image the presence of occluding flanks or retinally adjacent distant backgrounds is indicated by T-junctions. However, the presence of T-junctions inhibits induced contrast irrespective of the three-dimensional percept. The configurations in this paper refute the notions that perceived coplanarity or perceptual belonging necessarily enhance induced contrast.