Spatial Perception and Mental Rotation Produce Gender Differences in Cerebral Hemovelocity: A TCD Study

We sought to determine if gender differences in cerebral blood flow velocity emerge while persons performed cognitive tasks known to favor men, e.g., tests of spatial abilities. Bilateral measures were obtained simultaneously from the middle cerebral artery (VMCA) by transcranial Doppler sonography while men and women college students performed 31-s thinking tasks. Tests of spatial ability included (1) three spatial visualizing tasks (finding words among sets of letters, locating pictures hidden within a complex scene, and finding embedded geometric patterns), and (2) a mental rotation task. Two nonspatial visualizing control tasks were looking at (1) a list of words and (2) a set of pictures. Women had significantly faster global VMCAs than men during all tasks except looking at pictures. Two tasks (looking at pictures, mental rotation) produced hemispheric asymmetry (right > left) in women only. Gender differences in the number of correct responses occurred for finding words (women > men) and mental rotation (paradoxically, men > women) but not the other tests of spatial abilities. Our study shows that transcranial Doppler sonography provides noninvasive, real-time physiological indices of gender differences in spatial abilities.