Mental rotation of laterally presented random shapes in males and females.

Eighteen right-handed subjects (9 males, 9 female) were to decide if laterally presented random shapes were identical or a mirror image of a centrally presented standard shape. The lateral shapes were rotated over 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, or 300 degrees. For unrotated (0 degrees) mirror image stimuli, females showed a significant right visual-field advantage, whereas males showed no significant hemifield effect. The rate of rotation was equivalent for both sexes. Field of presentation did not affect the rotation rate either. The present results support a growing number of findings that indicate that the interpretation of mental rotation as a typical right-hemispheric spatial-processing task is questionable.