Abstract
Previous studies have revealed that object-centered and environmental frames of reference are involved in mentally representing an object and its spatial transformations. This study examined the relative contributions of each reference frame to the process of mental rotation. We devised ambiguous mental rotation stimuli consisting of planar disk objects, with a one-parameter family of possible axes of rotation between target and test objects. The possible axes included both an object's intrinsic axis for minimum rotation and an environmental axis (vertical or horizontal). Participants were first required to imagine smooth one-shot rotation of the test object to the orientation of the target object. They then reproduced the direction of an arrow depicted on the top face of the test object after imagined rotation, from which the axis being used for mental rotation was estimated. The results demonstrate that when competing with the intrinsic axes, the vertical axis was more effectively used for mental rotation, but the horizontal axis was rarely used. Further analysis suggests that a viewer rotation strategy may be responsible for the small amount of mental rotation around the environmental axes. These findings are consistent with a view that multiple frames of reference are interactively engaged for mental manipulation of objects.
