This paper demonstrates that the human operator's control characteristics in the two dimensional manual tracking system have an anisotropy with respect to vertical and horizontal directions when the polarity of the control input is reversed by the controlled object. Several kinds of the experimental conditions have been used to ascertain that the anisotropy is related to the visual space transformation, which is assumed to be one of the integration functions of multi-sensory information in the central nervous system. It has been suggested that the processing time in the central nervous system for reinterpreting the visual space constructed by the reversed coordinates varies with the kind of the controlled object. A hypothesis that the time difference between the horizontal reversal and the vertical reversal causes the anisotropy is proposed. This implies that the anisotropy is derived from the bilaterality in the brain.
