- dimensions of visual imagery
- A term introduced during the early 1970s by the American psychopharmacologists Ronald K. Siegel and Murray E. Jarvik to denote a classification of the phenomenological characteristics of *cannabis-induced visual imagery. More specifically, Siegel and Jarvik's classification constitutes an arrangement of regularly recurring forms that can be discerned among the numerous manifestations of cannabis-induced * geometric hallucinations. This arrangement comprises (1) a form dimension (including the categories random, line, curve, web, lattice, tunnel, spiral, kaleidoscopic, and complex), (2) a colour dimension (including the categories black, violet, blue, green, yellow, orange, red, brown, and white), (3) a movement dimension (including the categories aimless, horizontal, oblique, explosive, concentric, rotational, and pulsating), and (4) a dimension of action patterns (including the categories complete image changes, changes within a single image, combining of images, repeating of images, and overlaying of images). Siegel and Jarvik's classification was patterned on that of mescaline-induced * form-constants published in 1928 by the German-American biological psychologist and philosopher Heinrich Klüver (1897-1979). Both classifications may be seen as elaborations of the work of the 19th-century French physician Pierre Dheur on recurrent patterns of movement and disappearance in individuals experiencing * visual hallucinations.ReferencesDheur, P. (1899). Les hallucinations volontaires (l'état hallucinatoire). Suivi d'un chapitre sur les hallucinations. Notes manuscrites et inédites du Dr. J. Moreau (de Tours). Paris: Société d'Éditions Scientifiques.Klüver, H. (1966). Mescal and Mechanisms ofhallucinations. Chicago, IL: University of Chicago Press.Siegel, R.K., Jarvik, M.E. (1975). Drug-induced hallucinations in animals and man.In: Hallucinations. Behavior, experience, and theory.Edited by Siegel, R.K., West, L.J. New York, NY: John Wiley & Sons.
Dictionary of Hallucinations. J.D. Blom. 2010.