DUAL SYSTEM EXPERIENCE

   A term introduced in or shortly before 1928 by the German-American biological psychologist and philosopher Heinrich Klüver (1897-1979) to denote a visual experience that may arise in mescaline intoxication, involving the radical difference between two groups of phenomena. As Klüver wrote, "The hues, shapes, designs and movements, etc. in one group seem radically different from those of the other group. Thus the observer has the feeling of viewing two 'systems' or even two 'antagonistic' systems as he may refer to them, e.g. as 'solar' or 'polar' systems. Frantic motion may be typical of one system while slow majestic movements are characteristic of the other one. In psychotic states these two systems the differences of which are merely differences in visual properties may gain 'cosmic significance'."

   References

   Klüver, H. (1966). MescalandMechanismsofhal-lucinations. Chicago, IL: University of Chicago Press.