Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.

The parietal cortex is considered to be part of a network of brain areas that modulates competitive interactions between targets and irrelevant distracters in early visual cortex, however there is currently little causal evidence to support this in human observers. It is also unclear as to whether p...

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Những tác giả chính: Snow, J, Miranda, R, Humphreys, G
Định dạng: Journal article
Ngôn ngữ:English
Được phát hành: 2013
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author Snow, J
Miranda, R
Humphreys, G
author_facet Snow, J
Miranda, R
Humphreys, G
author_sort Snow, J
collection OXFORD
description The parietal cortex is considered to be part of a network of brain areas that modulates competitive interactions between targets and irrelevant distracters in early visual cortex, however there is currently little causal evidence to support this in human observers. It is also unclear as to whether parietal influences on visual perception in humans are limited to the contralesional hemispace or whether a unilateral lesion affects visual sensitivity bilaterally. Here we examined visual sensitivity in two patients with spatial neglect and extinction arising primarily from left-parietal damage. We used a sensitive psychophysical task based on those previously used to demonstrate loss of stimulus selection after lesions to extrastriate cortex. Observers discriminated the orientation of a lateralized suprathreshold target grating that appeared alone or in the context of nearby salient disc distracters. For parietal patients, target sensitivity within both the contralesional and ipsilesional fields was compromised by the presence of distracters. Conversely, healthy matched controls were unaffected by distracters. These results indicate that parietal cortex damage can influence visual perception within both the ipsi- as well as the contralesional field.
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spelling oxford-uuid:69561b56-b24e-477c-ba2f-44e40955f4562022-03-26T18:50:33ZImpaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:69561b56-b24e-477c-ba2f-44e40955f456EnglishSymplectic Elements at Oxford2013Snow, JMiranda, RHumphreys, GThe parietal cortex is considered to be part of a network of brain areas that modulates competitive interactions between targets and irrelevant distracters in early visual cortex, however there is currently little causal evidence to support this in human observers. It is also unclear as to whether parietal influences on visual perception in humans are limited to the contralesional hemispace or whether a unilateral lesion affects visual sensitivity bilaterally. Here we examined visual sensitivity in two patients with spatial neglect and extinction arising primarily from left-parietal damage. We used a sensitive psychophysical task based on those previously used to demonstrate loss of stimulus selection after lesions to extrastriate cortex. Observers discriminated the orientation of a lateralized suprathreshold target grating that appeared alone or in the context of nearby salient disc distracters. For parietal patients, target sensitivity within both the contralesional and ipsilesional fields was compromised by the presence of distracters. Conversely, healthy matched controls were unaffected by distracters. These results indicate that parietal cortex damage can influence visual perception within both the ipsi- as well as the contralesional field.
spellingShingle Snow, J
Miranda, R
Humphreys, G
Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title_full Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title_fullStr Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title_full_unstemmed Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title_short Impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage.
title_sort impaired visual sensitivity within the ipsilesional hemifield following parietal lobe damage
work_keys_str_mv AT snowj impairedvisualsensitivitywithintheipsilesionalhemifieldfollowingparietallobedamage
AT mirandar impairedvisualsensitivitywithintheipsilesionalhemifieldfollowingparietallobedamage
AT humphreysg impairedvisualsensitivitywithintheipsilesionalhemifieldfollowingparietallobedamage