Canal rotation vectors, viewed looking from positive values of each axis toward the origin. Top row indicates direction of view relative to the head. Canal plane normal directions, solid lines; prime directions, dotted lines. Horizontal canals, circles; anterior canals, squares; posterior canals, diamonds. Left side, open symbols; right side, solid symbols. Polarity of each vector assigned so that an excitatory rotation of the canal and the positive direction of the vector corresponds via the right-hand rule.