sons for the lack of closure. The problem in this figure is that the visual system
does not know where the evidence is incomplete. Look at what happens when
the picture is shown with the mask present as in figure 9.14. The visual system
quickly joins the fragments without the observer having to think about it. The
Gestalt principle of closure has suddenly come alive in the presence of the
mask.
What information could the mask be providing? It tells the eye two things. It
explains which contours have been produced by the shape of the fragments
themselves as contrasted with those that have been produced by the shape of
the mask that is covering them. It also provides information about occlusion
(which spaces between fragments were created by the fact that the mask
Figure 9.13
Fragments do not organize themselves strongly when there is no information for occlusion. (From
Bregman 1981.)
Figure 9.14
The same fragments shown in figure 9.13, except that information for occlusion has been added,
causing the fragments on the boundaries of the occluding form to be grouped. (From Bregman
1981.)
The Auditory Scene 233