Mental rotation and handedness: differences in object-based and egocentric transformations

This study investigates mental rotation performance of right- and left-handers in object-based and egocentric mental rotation tasks using human body stimuli with an outstretched arm in front and back view. Previous literature suggests that right-handers show a slightly better mental rotation performance than left-handers. 42 participants, 14 left-handers and 28 right-handers, completed a mental rotation task with object-based and egocentric transformation of a human figure which was displayed either in front or back view. The main result was a three-way interaction between the factors “kind of transformation”, “handedness” and “view” in a way, that right-handers show significantly faster reaction times then left-handers in front view object-based transformations because of the additional in-depth rotation for front view stimuli. This difference disappeared in egocentric tasks due to the modification of onés own perspective to solve the task. The results of this study show that right-handers not generally outperform left-handers in mental rotation tasks but only if more cognitive resources are needed.