trailing phenomenon

   Also known as trailing effect and tracers. The first two terms were introduced in or shortly before 1971 by the American psychiatrist and addiction specialist Harvey Asher to denote a visual phenomenon which is associated with the (prior) use of "hallucinogens such as LSD, and which is characterized by a series of discontinuous stationary images that trail behind a moving object or stimulus. As Asher asserts, " 'Trailing effect' is the term used to describe seeing a moving object not as an individual entity in motion but in serial, momentarily stationary positions. If the observer moves his finger across his field of vision, he not only sees his finger moving as a single object, but also sees the various individual movements needed to make up the complete movement. It is like a slow-motion multiple exposure effect. Although this is first seen while the person is under the acute influence of the drug, some LSD users report that it remains with them for up to one year after drug ingestion." In addition to their occurrence during the acute stages of intoxication with hallucinogens such as LSD, and during "flashback episodes, the trailing phenomenon has also been reported in the context of "hallucinogen-induced persistent perception disorder (HPPD). Conceptually as well as phenomenologically, the trailing phenomenon may be considered a variant of " visual perseveration, which is itself classified as a "reduplicative phenomenon or a type of " metamorphopsia.
   Asher, H. (1971). "Trailing" phenomena - A long-lasting LSD side effect. American Journal of Psychiatry, 127, 1233-1234.

Dictionary of Hallucinations. . 2010.

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