They then showed involuntary completion of the grid elements into a surface interacting with the static targets - creating an illusion of occlusion. When the grid appeared in front of the targets the proportion of disappearance was larger than when it was behind or on the same plane. Although to a lesser extent, MIB did nonetheless occur in the conditions where the perceptual occlusion was not taking place (targets were in front of the mask).
They then displayed spontaneous filling-in of grid elements onto a surface interacting with stationary objects - creating an illusion of concealment. When the grid appeared in front of the objects, the proportion of disappearance increased compared to when it was behind or on the same plane. Although to a lesser degree, MIB (masking-induced blindness) still occurred even when perceptual occlusion was not taking place.