This study investigated the mechanism by which human vision determines the orientation of depth-rotated familiar objects. We hypothesized that the symmetry of the contours in the front and back views of objects is used to determine their orientation because familiar objects are often bilaterally symmetrical. The participants were required to detect 15°differences of depth orientation of the two objects presented simultaneously. Detection was better for the 0°(front) and 180°(back) conditions than for the 45°, 90°, and 135°conditions (Experiment 1). These results confirmed a predicted contribution of symmetry. The same pattern of results was observed when detection was required of an orientation difference of two different objects (Experiment 2).
The Japanese Journal of Psychonomic Science 25 (1), 105-106, 2006
The Japanese Psychonomic Society