Perceptual extrapolation of a stereo-scopically raised surface depends upon its spatial frequency content

Purpose. When a convex part of a flat figure is stereoscopically displaced forward, the raised surface appears to continue over the remaining portion of the figure. Factors affecting such perceptual extrapolation were investigated. Method. The spatial extent of the extrapolated area was measured as a function of the height, width and spatial frequency content of the raised region. Results. The extrapolated area was significantly wider when the spatial frequency was lower, whears the other factors, including the degree of binocular disparity, had no significant effect. Discussions. These results are discussed in relation to the function of the visual system to conduct modal and amodal surface completion.