Cite as:
Martelli M L, 1999, "Motion and depth modulate the hierarchical organisation effect" Perception 28 ECVP Abstract Supplement

Motion and depth modulate the hierarchical organisation effect

M L Martelli

When a vertical rod is presented within a tilted square frame, it is perceived, according to the frame-of-reference effect, to be tilted in the opposite direction to the frame tilt. In central double-frame displays (DFDs) a vertical rod is presented within two concentric square frames, the outer tilted and the inner upright. Observers perceive the vertical rod tilted in the same direction as the outer frame. This finding has been attributed to hierarchical organisation (HO) (Zoccolotti et al 1997 Perception 26 1485 - 1494). Only the illusory tilt of the inner frame, induced by the outer frame, influences the perceived orientation of the rod. In previous studies with DFDs, we used a forced-choice procedure, which commonly produces results equivalent to the adjustment method. Here we report a difference between the two methods. The adjustment procedure fails to produce the HO effect. We hypothesise that this result is due to the DFD not being perceived as a single object. Motion breaks the relation between the rod and the inducing stimuli and a frame-of-reference effect is shown. In order to evaluate this hypothesis, we have conducted a series of experiments using stereoscopic DFDs to segregate the elements by depth.

These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 1999 Abstract Supplement (complete) size: 1478 Kb