simultanagnosia


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Related to simultanagnosia: ventral simultanagnosia

simultanagnosia

 [si″mul-tān″ag-no´zhah]
the inability to comprehend more than one element of a visual scene at the same time or to integrate the parts as a whole.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

si·mul·tan·ag·no·si·a

(sī'mul-tān'ag-nō'sē-ă),
Inability to recognize multiple elements in a visual presentation, that is, one object or some elements of a scene can be appreciated but not the display as a whole.
Synonym(s): simultagnosia
[simultaneous + agnosia]
Farlex Partner Medical Dictionary © Farlex 2012

simultanagnosia

A rare neurologic defect characterised by an inability to comprehend more than one element of a scene at the same time or integrate the parts into a whole, which is attributed to a defect in visuospatial processing.

Types
• Dorsal simultanagnosia.
• Ventral simultanagnosia.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

simultanagnosia

Neurology Inability to comprehend > 1 element of a scene at the same time or integrate the parts into a whole
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

si·mul·tan·ag·no·si·a

(sī'mŭl-tān'ag-nō'sē-ă)
Inability to recognize multiple elements in a visual presentation; i.e., one object or some elements of a scene can be appreciated but not the display as a whole.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

simultanagnosia 

Inability to comprehend a whole picture or sustain visual attention across simultaneous elements, although its constituent elements may be recognized. Objects may look fragmented or even sometimes disappear hence the patient may have difficulty recognizing a face as only one part is seen, or difficulty reading. Visual acuity and visual fields are normal. This is often a symptom of Balint's syndrome or the result of a lesion, usually, in both parietal visual cortices, although temporal lobes may also be involved. Syn. simultagnosia; visual disorientation. See Balint's syndrome.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Moreover, it suggests that simultanagnosia could be a possible predictor of DLB, in particular, during the MCI phase of the disease.
An ad hoc version of Navons letters task was administered to BG and also to a small group of healthy control participants (n = 6) to assess simultanagnosia. The mean age of the control group was comparable to BG (mean = 88.83, SD = 4.74, range = 85-99 years), while education was slightly superior (mean = 10.5, SD = 4.75, range = 5-18).
A significant deficit, suggesting simultanagnosia, appeared on Navon's letters task (BG's performance = 30/60; mean control performance = 52.5, SD = 6.5; t = -3.205, P =.024, two-tailed).
Simultanagnosia is an attentional disorder in which patients can only perceive a single object within a visual scene at any one time, for example, as in Figure 2.
It is characterized by optic ataxia (lack of co-ordination of hand and eye movement), oculomotor apraxia (the inability to voluntarily guide eye movements/change to a new location of visual fixation), and simultanagnosia (the inability to perceive more than one object at a time, even when in the same place).
Simultanagnosia with or without optic ataxia or ocular apraxia ii.