STIMULUS DIMENSIONALITY EFFECTS IN MENTAL ROTATION

Do 3-dimensional (3-D) figures require more time to rotate mentally th an do 2-dimensional (2-D) figures? This question was examined in 2 exp eriments incorporating 15 2-D and 15 3-D stimuli. For 3-D stimuli, blo ck figures were used of the type used by R. N. Shepard and J. Metzler in their classic studies. For 2-D stimuli, block figures were also use d, but with all cubes in a single plane, resulting in 2-D and 3-D figu res matched on surface features. Three-D figures elicited steeper slop es than did 2-D figures, supporting the view that the mental rotation of visual representations is sensitive to stimulus dimensionality. The authors summarize the results of several mental rotation studies that investigated stimulus dimensionality and suggest that the evidence ac ross studies is consistent with the present finding. They discuss 2 pl ausible loci for the dimensionality effect in S. M. Kosslyn's (1980) t heory of mental imagery.