Role of motor processes in extrinsically encoding mental transformations.

Previous research has shown that imagined perspective rotations elicit spatial and low-level cortical motor areas of the brain when participants rely on knowledge of their physical body, or body percept (Wraga, Flynn, Boyle, & Evans, 2010). The current study used functional magnetic resonance imaging (fMRI) to investigate whether recruitment of the body percept would activate low-level cortical motor areas of the brain within other classes of mental transformations. Participants performed imagined object and perspective rotations of three-dimensional Shephard-Metzler (1971) stimuli. For each task, participants used button presses serving as virtual pointers to locate a prescribed portion of the stimuli with respect to their "right" and "left." We found low-level cortical motor activation (M1) for both mental transformations; however, the degree to which such activation related to participants' performance differed, as well as the recruitment of additional nonmotoric strategies. The results are discussed in terms of recent hypotheses regarding the role of the body percept in extrinsically encoded mental transformations.