The term imaginal polyopia is indebted to the Latin verb imaginari (to copy, to imitate, to picture) and the Greek words polus (much, many) and opsis (seeing). It was introduced in or shortly before 1928 by the German-American biological psychologist and philosopher Heinrich Klüver (1897-1979) to designate a special form of "polyopia which he observed in the context of mescaline intoxication. In imaginal polyopia the perception of part of an object can give rise to the subjective sensation of seeing it in its entirety, and the subsequent notion that multiple versions of the object exist. Klüver illustrates this phenomenon by quoting a participant in a mescaline experiment: "M. passed me on my left side. I saw nothing but a part of his cloak. Automatically it turned into the whole figure of M.; and I had now some sort of idea that a large number of M.'s moved away from me in a curved line, the M. in the foreground being the smallest one. I was unable to say whether it was a very strong image or vision; phenomenally, the many M.'s were projected into the perceived space of the dark room." Klüver uses the term imaginal polyopia in opposition to "'objective' polyopia and "hallucinatory polyopia.
References
Klüver, H. (1966). Mescal and Mechanisms of hallucinations. Chicago, IL: University of Chicago Press.
Dictionary of Hallucinations. J.D. Blom. 2010.