positive afterimage
   A term used to denote an afterimage that has the same relative brightness relations as the primary optical stimulus (for example, a dark blue afterimage of a dark blue pen). The term positive afterimage is used in opposition to the term * negative afterimage, which refers to an afterimage that manifests itself in complementary colours (for example, a dark blue afterimage of a bright yellow pen). Two physiologically occurring positive afterimages are *Hering's afterimage and the * Hess afterimage. The occurrence of pathological positive afterimages has been reported in drug-induced states such as LSD and mescaline intoxication, as well as in drug-induced * flashback phenomena and *hallucinogen-induced persistent perception disorder (HPPD). Phenomenologically as well as conceptually, these latter types of positive afterimage would seem to be closer akin to central phenomena such as *palinopsia, *polyopia, and the * trailing phenomenon, than to physiological afterimages, which are generally considered to be * entoptic in origin. The positive afterimage may be classified as a * physiological illusion.
   References
   Abraham, H.D. (1983). Visual phenomenology of the LSD flashback. Archives of General Psychiatry, 40, 884-889.
   Brown, J.L. (1965). Afterimages.In: Vision and visual perception. Edited by Graham, C.H. New York, NY: Wiley.

Dictionary of Hallucinations. . 2010.

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  • positive afterimage — n a visual afterimage that retains the same light, dark, and color relationships as those appearing in the original image compare NEGATIVE AFTERIMAGE * * * an afterimage in which the bright, dark, and colored areas are the same as in the original …   Medical dictionary

  • positive afterimage — teigiamasis povaizdis statusas T sritis fizika atitikmenys: angl. positive afterimage vok. positives Nachbild, n rus. положительное послеизображение, n pranc. postimage positive, f …   Fizikos terminų žodynas

  • positive afterimage — noun : a visual afterimage that retains the same light, dark, and color relationships as those appearing in the original image opposed to negative afterimage …   Useful english dictionary

  • afterimage —    Also referred to as aftersensation, afterimagery, and post image. All three terms are used to denote a group of visual percepts that occur in response to a primary light stimulus to the eye, typically noticed after the stimulus has been… …   Dictionary of Hallucinations

  • Afterimage — For other uses, see Afterimage (disambiguation). If the viewer stares at this image for 20 60 seconds and stares at a white object a negative afterimage will appear (in this case being cyan on magenta). This can also be achieved by the viewer… …   Wikipedia

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  • afterimage — Persistence of a visual response after cessation of the stimulus. SYN: accidental image, negative image. negative a. a. in which the lightness relationship is reversed; if chromatic, it appears in complementary color. positive a. a. in which the… …   Medical dictionary

  • Hering's afterimage —    The eponym Hering s afterimage refers to the German psychologist and physiologist Karl Ewald Konstantin Hering (1834 1918). It is used to denote a positive afterimage that appears first in a temporal sequence of afterimages resulting from a… …   Dictionary of Hallucinations

  • Hess afterimage —    The eponym Hess afterimage refers to the German ophthalmologist Carl von Hess (1863 1923). It is used to denote a positive afterimage that appears third in a temporal sequence of afterimages resulting from a brief light stimulus. Hess… …   Dictionary of Hallucinations

  • negative afterimage —    Also known as Purkinje afterimage. The adjective negative refers to the fact that the colours of this type of * afterimage are complementary to the colours of the primary stimulus. The term negative afterimage is used in opposition to… …   Dictionary of Hallucinations

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