Left-hand advantage in right-handers for spatial constant error: preliminary evidence in a unimanual ballistic aimed movement.

While the superiority of the right hemisphere for the processing of spatial relationships in normal right-handers has been largely accepted, it is surprising that evidence for an advantage of the left "nondominant" hand over the right "dominant" hand in spatial motor tasks is up to now almost totally lacking. We report preliminary evidence that normal right-handers perform open-loop ballistic aimed movements with a smaller constant error when using the left rather than the right hand. In addition, constant error is found to be minimal for movements directed toward the left half-field.