describes the situation in which patients are unable to recognise stimuli visually; however, they may be able to use other senses or logical reasoning to aid identification.
Specifically, they address integrative visual agnosia
, picture identification, visual search and stimulus similarity, orthographic processing in visual word identification, non-spatial extinction following lesions of the parietal lobe, visual marking, action-based effects on object selection, theory of mind, memory-based guidance on visual selection, the salience of stimuli in selecting visual information, learned conjunctive relations, social attention, and cognition and stroke.
2) Clinical features of PCA constitute a wide variety of signs and symptoms; nevertheless, the most frequent include hemiagnosia (deficit in awareness of one side of space), optic ataxia (lack of coordination between visual inputs and hand movements, resulting in inability to reach and grab objects), visual agnosia
(an impairment in recognition of visually presented objects), alexia (difficulty to understand written words), acalculia (difficulty with simple mathematical tasks), and agraphia (loss in the ability to communicate through writing).
A case study in visual agnosia
revisited; to see but not to see, 2d ed.
Anecdotal cases have been published referring to acute aphasia (Devere, Trotter, & Cross, 2000), alexia with agraphia (Day, Fisher, & Mastaglia, 1987), alexia without agraphia (Dogulu, Kansu, & Karabudak, 1996; Mao-Draayer & Panitch, 2004), visual agnosia
(Okuda et al.
The case presented above exhibited five typical symptoms of KBS, except for visual agnosia
, and may be considered as an incomplete form of the syndrome.