Carpenter, M. & Proffitt, D. R. (2001). Comparing viewer and array mental rotations in different planes. Memory & Cognition, 29, 441-448.
Participants imagined rotating either themselves or an array of objects that surrounded them. Their task was to report on the egocentric position of an item in the array following the imagined rotation. The dependent measures were response latency and number of errors committed. Past research has shown that self-rotation is easier than array rotation. However, we found that imagined egocentric rotations were as difficult to imagine as rotations of the environment when people performed imagined rotations in the midsagittal or coronal plane. THe advantages of imagined self rotations are specific to mental rotations performed in the transverse plane.