The relative contribution of contact and target lines in the magnitude of the Poggendorff effect

It is well known that a set of parallel lines can cause misperception of the projected path of an oblique. Most studies of this effect have emphasized either the proximal or the distal stimulus components--the line with which the oblique makes contact, or the line that serves as the target of the projection. An experiment is reported in which the relative contribution of the contact and target lines was examined. The results indicate that rotation of either line can determine the magnitude of the projection error.