visual agnosia


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Related to visual agnosia: prosopagnosia, optic ataxia

agnosia

 [ag-no´zhah]
inability to recognize the import of sensory impressions; the varieties correspond with several senses and are distinguished as auditory (acoustic), gustatory, olfactory, tactile, and visual.
finger agnosia loss of ability to indicate one's own or another's fingers.
tactile agnosia inability to recognize familiar objects by touch. See also astereognosis.
time agnosia loss of comprehension of the succession and duration of events.
visual agnosia inability to recognize familiar objects by sight, usually due to a lesion in one of the visual association areas. Called also object blindness and psychic blindness.
visual-spatial agnosia (visuospatial agnosia) lack of the ability to analyze and orient using visual representations and their spatial relationships.

vis·u·al ag·no·si·a

inability to recognize objects by sight; usually caused by bilateral parietooccipital lesions.
Synonym(s): optic agnosia

visual agnosia

visual agnosia

 Neurology An inability to recognize objects and people, a common finding in parietal lobe tumors. See Agnosia.

vis·u·al ag·no·si·a

(vizh'ū-ăl ag-nō'zē-ă)
Inability to recognize objects by sight; usually caused by bilateral parietooccipital lesions.

visual agnosia (ag·nōˑ·zh),

n the lack of ability to use one's sense of sight to distinguish objects even though eyesight is intact.
References in periodicals archive ?
Whereas visual agnosia causes patients to be unable to recognise stimuli, visual anomia (also referred to as optic aphasia), (17) is a condition in which patients are incapable of naming objects due to damaged connections between the visual and language centres of the brain.
In the neuropsychological evaluation, severe cognitive deficits were found: apperceptive visual agnosia, spatial agnosia, constructional apraxia, ideomotor apraxia and a significant alteration in coding and recovery of verbal episodic memory.
Patient assessments: Patients' cognitive function was assessed using the MMSE [11], the Abbreviated Mental Test Score (AMTS) [13] and by a selection of tests from the CAMCOG component of the CAMDEX [8], including those examining praxis and visual agnosia.
Reading problems are associated with some forms of visual agnosia (see Farah, 1990), and, in a detailed case study of one agnosic patient (HJA), Humphreys & Riddoch (1987) argued that the impairment to his early visual processing was such that there would be impoverished parallel processing of letters in words (and hence an impoverished input to the visual word recognition system).
These men suffer from profound visual agnosia - a glove, a rose, a loved one are no longer recognizable to them.
Table 1 General symptoms resulting from stroke * Headaches * Mental confusion, disorientation and memory deficits * Aphasia * Agnosia * Apraxia * Seizures * Vertigo * Dysarthria * Incontinence * Hemiplegia or hemiparesis * Perceptual defects Table 2 Common vision impairments resulting from stroke * Strabismus * Gaze palsy * Nystagmus * Diplopia * Lagophthalmos * Dry eye * Visual acuity reduction * Visual field defects * Unilateral neglect * Visual midline shift * Visual agnosia * Cortical blindness * Photophobia * Contrast sensitivity impairment * Visual hallucinations * Light and dark adaptation impairment