- Riddoch's phenomenon
- Also known as Riddoch syndrome and statico-kinetic dissociation. Both terms are used to denote a "blindness to stationary light stimuli, combined with an unaffected conscious perception of moving light stimuli. Riddoch's phenomenon is associated with "cerebral amblyopia, a disorder of visual perception due to retrochi-asmal lesions to the visual system which spare area V5, the specialized motion area ofthe visual cortex. The condition is named after the Scottish neurologist George Riddoch (1888-1947), who was the first to describe it in 1917, on the basis of observations of soldiers returning from World War I with gunshot wounds affecting the calcarine cortex. On the basis of those same observations, Riddoch suggests that movement constitutes a special aspect ofvisual perception, to be distinguished from the perception of light, form, and colour. Conceptually, Riddoch's phenomenon constitutes the counterpart of "akinetopsia (i.e. the inability to see motion).ReferencesRiddoch, G. (1917). Dissociation of visual perceptions due to occipital injuries, with especial reference to appreciation of movement. Brain, 40, 15-57.Zeki, S., ffytche, D.H. (1998). The Riddoch syndrome: Insights into the neurobiology of conscious vision. Brain, 121, 25-45.
Dictionary of Hallucinations. J.D. Blom. 2010.
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Riddoch syndrome — see Riddoch s phenomenon … Dictionary of Hallucinations
Riddoch phenomenon — The Riddoch phenomenon is an ocular affection giving the person the ability to only distinguish moving objects in a blind field, static ones being invisible to this person. The moving objects have no color or shape characteristics for him,… … Wikipedia
Riddoch — George, British physician, 1888–1947. See R. phenomenon. SEE ALSO: R. phenomenon … Medical dictionary
phenomenon — 1. A symptom; an occurrence of any sort, whether ordinary or extraordinary, in relation to a disease. 2. Any unusual fact or occurrence. [G. phainomenon, fr. phaino, to cause to appear] adhesion p. a p. manifested by the adherence of antigen… … Medical dictionary
akinetopsia — Also referred to as cerebral akinetopsia and visual motion blindness. The term akinetopsia comes from the Greek words akinesia (absence of motion) and opsis (seeing). It was introduced in or shortly before 1991 by the British neurobiologist… … Dictionary of Hallucinations
cerebral amblyopia — The term cerebral amblyopia is indebted to the Greek noun ambluopia, which means weakness of vision. It refers to a variant of * amblyopia, or diminished visual acuity, attributed to a lesion affecting the retrochiasmal part of the visual… … Dictionary of Hallucinations
statico-kinetic dissociation — see Riddoch s phenomenon … Dictionary of Hallucinations
Cortical blindness — Classification and external resources ICD 10 H47.6 ICD 9 377.75 … Wikipedia