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Rehabilitation of Visual Perceptual and Visual Spatial Disorders in Adults and Children
Published in Barbara A. Wilson, Jill Winegardner, Caroline M. van Heugten, Tamara Ownsworth, Neuropsychological Rehabilitation, 2017
Barbara A. Wilson, Joe Mole, Tom Manly
Visual object agnosia is the inability to recognise objects despite adequate eyesight and naming ability; ‘a normal percept stripped of its meaning’ (Teuber, 1968). One distinction still widely used today is between associative and apperceptive agnosia (Lissauer, 1890). People with apperceptive agnosia cannot draw, match or point to objects named by the examiner, and are often thought to be blind. Objects, faces, letters and shapes can be affected and simultanagnosia, an inability to see more than one object or even part of an object at a time, is common (Wilson, 1999; Zoltan, 2007). In contrast, people with associative agnosia can copy and match and are not considered to be blind although may have problems identifying faces, colours and words (Farah, 2004).
Disruptions in physical substrates of vision following traumatic brain injury
Published in Mark J. Ashley, David A. Hovda, Traumatic Brain Injury, 2017
The last area of classification is that of disorders of higher visual processing. Although an oversimplification, the easiest approach to conceptualize disorders of higher visual perceptual and visual spatial processing is to think of disconnections in either the ventral or dorsal streams. Disconnections involving the ventral stream can be classified as visual/visual, visual/verbal, or visual/limbic. Visual/visual disconnections result in agnosia. Agnosia refers to the clinical condition in which the patient is able to perceive visual stimuli and has preserved language capacity to name the visual representation but recognition is lost. These conditions include the loss of recognition of object features, object identity, faces, places, and color. These conditions are named, respectively, visual apperceptive, visual associative agnosia, prosopagnosia, topographagnosia, and color agnosia. Apperceptive visual agnosia is the condition in which the patient cannot distinguish one form from another whereas visual associative agnosia is the disturbance of visual recognition with intact visual perception. Loss of connectivity between visual/verbal systems results in pure alexia, color anomia, and object anomia. Visual anomia indicates recognition is intact but the ability to name the entity is impaired. Impaired linkages between visual/limbic areas result in visual amnesia and hypoemotionality with the latter including the inability to recognize facial expressions.
ENTRIES A–Z
Published in Philip Winn, Dictionary of Biological Psychology, 2003
To identify a visual object, what is seen must make contact with previous experience organized in terms of specific episodes and general conceptual knowledge. Associative agnosia refers to impairments of object identification that are demonstrably the outcome of some failure in the mapping of structure to object concepts: what is correctly seen is no longer adequately classified and understood. AGNOSIA may be more severe for objects in particular categories. In addition, the disorder may occur in the auditory or tactile modality, and not in visual perception.
Current practice and challenges in screening for visual perception deficits after stroke: a qualitative study
Published in Disability and Rehabilitation, 2022
Kathleen Vancleef, Michael J. Colwell, Olivia Hewitt, Nele Demeyere
Visual perception is the dynamic process of perceiving the environment through sensory inputs and translating the sensory input into meaningful concepts associated with visual knowledge of the environment [1]. Visual perception problems are therefore distinct from sensory visual impairments such as reduced visual acuity, visual field and eye movements [2]. Where sensory visual impairments result from damage to the eye or early visual pathways from the eye to the primary visual cortex, visual perception deficits are attributed to impaired function in later visual processing areas in the occipital, parietal and temporal cortex [3]. Examples of visual perceptual deficits include apperceptive and associative agnosia (object recognition difficulties), prosopagnosia (face recognition difficulties), akinetopsia (difficulties in perceiving motion), achromatopsia (difficulties in perceiving colour), problems in visual memory (remembering what you have seen before), and in visuospatial abilities (e.g., judging distances or spatial relations between objects) [3]. Visual inattention or hemispatial neglect is sometimes considered to be part of visual perception [1,4], though neuropsychology research attributes this to an attentional deficit [5]. In particular, the presence of preserved perception when attention is stretched to focus on the stimuli, the existence of cross-modal neglect and manipulations of stimulus density on the extent of neglect support the classification of hemispatial neglect as a disorder of attention [6,7].
Therapist-assisted vision therapy improves outcome for stroke patients with homonymous hemianopia alone or combined with oculomotor dysfunction
Published in Neurological Research, 2018
Peter Smaakjær, Signe Tornøe Tødten, Rune Skovgaard Rasmussen
The exclusion criteria were patients with reduced ability to perceive visual impressions correctly (apperceptive agnosia – defect in perception); ability to see clearly, but without the ability to associate what is seen with what is known. Reduced ability to recognise an object (associative agnosia – defect in association); inability to recognise more than one letter at a time or to recognise the form of a word. The patient sees only individual parts of a picture, but not the picture as a whole (simultanagnosia); patients with cognitive or physical problems who lack the motivation required to receive teaching or training in stereopsis; and markedly low scores in cognitive tests such as the Montreal Cognitive Assessment (MoCA) [13], Multidimensional Fatigue Inventory (MFI-20) [14,15] or the Rivermead Behavioural Memory Test [16], which would indicate an inability to complete the training. Furthermore it was expected that patients could take care of themselves in their own homes and not have memory problems that would prevent them from understanding or taking part in lessons.
The neuropsychological rehabilitation of visual agnosia and Balint’s syndrome
Published in Neuropsychological Rehabilitation, 2019
Joost Heutink, Dana L. Indorf, Christina Cordes
This study utilised the academic databases Psychinfo, Medline, and Amed to search for peer-reviewed publications published in either English or German. Keywords used were “treatment” or “rehabilitation” in combination with each of the terms “visual agnosia,” “simultanagnosia,” “object agnosia,” “prosopagnosia,” “associative agnosia,” “apperceptive agnosia,” “colour agnosia,” “form agnosia,” “semantic agnosia,” “topographical agnosia,” and “Balint’s syndrome” in either English or German translation. We did not define a certain time period for the inclusion of the listed results and did not include unpublished data. Abstracts of the listed results were reviewed to identify those articles addressing the topic at hand.