Posterior cortical atrophy: visuomotor deficits in reaching and grasping
Posterior Cortical Atrophy (PCA) is a rare clinical syndrome characterized by the predominance of higher-order visual disturbances such as optic ataxia, a characteristic of Balint's syndrome. Deficits result from progressive neurodegeneration of occipito-temporal and occipito-parietal cortices....
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Frontiers Media S.A.
2013
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689034/ |
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pubmed-36890342013-06-25 Posterior cortical atrophy: visuomotor deficits in reaching and grasping Meek, Benjamin P. Shelton, Paul Marotta, Jonathan J. Neuroscience Posterior Cortical Atrophy (PCA) is a rare clinical syndrome characterized by the predominance of higher-order visual disturbances such as optic ataxia, a characteristic of Balint's syndrome. Deficits result from progressive neurodegeneration of occipito-temporal and occipito-parietal cortices. The current study sought to explore the visuomotor functioning of four individuals with PCA by testing their ability to reach out and grasp real objects under various viewing conditions. Experiment 1 had participants reach out and grasp simple, rectangular blocks under visually- and memory-guided conditions. Experiment 2 explored participants' abilities to accurately reach for objects located in their visual periphery. This investigation revealed that PCA patients demonstrate many of the same deficits that have been previously reported in other individuals with optic ataxia, such as “magnetic misreaching”—a pathological reaching bias toward the point of visual fixation when grasping peripheral targets. Unlike many other individuals with optic ataxia, however, the patients in the current study also show symptoms indicative of damage to the more perceptual stream of visual processing, including abolished grip scaling during memory-guided grasping and deficits in face and object identification. These investigations are the first to perform a quantitative analysis of the visuomotor deficits exhibited by patients with PCA. Critically, this study helps characterize common symptoms of PCA, a vital first step for generating effective diagnostic criteria and therapeutic strategies for this understudied neurodegenerative disorder. Frontiers Media S.A. 2013-06-21 /pmc/articles/PMC3689034/ /pubmed/23801956 http://dx.doi.org/10.3389/fnhum.2013.00294 Text en Copyright © 2013 Meek, Shelton and Marotta. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Meek, Benjamin P. Shelton, Paul Marotta, Jonathan J. |
| spellingShingle |
Meek, Benjamin P. Shelton, Paul Marotta, Jonathan J. Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| author_facet |
Meek, Benjamin P. Shelton, Paul Marotta, Jonathan J. |
| author_sort |
Meek, Benjamin P. |
| title |
Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| title_short |
Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| title_full |
Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| title_fullStr |
Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| title_full_unstemmed |
Posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| title_sort |
posterior cortical atrophy: visuomotor deficits in reaching and grasping |
| description |
Posterior Cortical Atrophy (PCA) is a rare clinical syndrome characterized by the predominance of higher-order visual disturbances such as optic ataxia, a characteristic of Balint's syndrome. Deficits result from progressive neurodegeneration of occipito-temporal and occipito-parietal cortices. The current study sought to explore the visuomotor functioning of four individuals with PCA by testing their ability to reach out and grasp real objects under various viewing conditions. Experiment 1 had participants reach out and grasp simple, rectangular blocks under visually- and memory-guided conditions. Experiment 2 explored participants' abilities to accurately reach for objects located in their visual periphery. This investigation revealed that PCA patients demonstrate many of the same deficits that have been previously reported in other individuals with optic ataxia, such as “magnetic misreaching”—a pathological reaching bias toward the point of visual fixation when grasping peripheral targets. Unlike many other individuals with optic ataxia, however, the patients in the current study also show symptoms indicative of damage to the more perceptual stream of visual processing, including abolished grip scaling during memory-guided grasping and deficits in face and object identification. These investigations are the first to perform a quantitative analysis of the visuomotor deficits exhibited by patients with PCA. Critically, this study helps characterize common symptoms of PCA, a vital first step for generating effective diagnostic criteria and therapeutic strategies for this understudied neurodegenerative disorder. |
| publisher |
Frontiers Media S.A. |
| publishDate |
2013 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689034/ |
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1611988489615704064 |