A term used to denote a type of geometric visual hallucination or illusion associated primarily with the use of hallucinogens such as LSD and mescaline. The term cobweb figure was introduced in of shortly before 1928 by the German-American biological psychologist and philosopher Heinrich Klüver (1897-1979) to denote one of the four *form-constants of geometric visual hallucinations occurring during the initial stages of mescaline intoxication. Klüver uses the term form-constant to denote certain visual forms and elements that according to him "appear in almost all mescal visions". As he maintains, "many 'atypical' visions are upon close inspection nothing but variations of these form-constants." The examples of the cobweb figure given by Klüver, based on the observations of different test persons, are rendered by him as follows. "'Colored threads running together in a revolving center, the whole similar to a cobweb'; immense areas over which gigantic cobwebs were spread...'; cobweb-like forms...'." Klüver calls the remaining three form-constants * chessboard design, * tunnel, and * spiral.
References
Klüver, H. (1966). Mescal and Mechanisms of hallucinations. Chicago, IL: University of Chicago Press.
Dictionary of Hallucinations. J.D. Blom. 2010.