Organization of area hV5/MT+ in subjects with homonymous visual field defects.
Organization of area hV5/MT+ in subjects with homonymous visual field defects.
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DOI：
10.1016/j.neuroimage.2018.03.062
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发表时间：
2019-04-15
期刊：
影响因子：
5.7
通讯作者：
Smirnakis SM
中科院分区：
文献类型：
--
作者：
Papanikolaou A;Keliris GA;Papageorgiou TD;Schiefer U;Logothetis NK;Smirnakis SM
初级视皮层（V1）的损伤导致视野的视网膜定位对应部分中的视野损失（暗点）。尽管如此，在盲区内仍然存在少量的残余视觉敏感度。这种剩余容量与中颞区复合体（V5/MT+）中观察到的活动有关。然而，它仍然是未知的组织是否hV 5/MT+的变化后，早期视觉皮层病变。我们研究了组织的区域hV 5/MT+的5例患者的致密homeostomy的缺陷，在一个象限的视野作为一个结果的部分V1+或视放射病变。为此，我们开发了一种新方法，该方法直接从视觉皮层中每个体素的BOLD信号中模拟群体感受野的边界。我们发现hV 5/MT+的反应在所有患者的暗点内产生，并确定了两种可能的激活来源：1）反应可能起源于与暗点对应的V1区的部分受损部分，2）反应也可以独立于V1区的输入，这表明存在功能性V1旁路通路。显然，在hV 5/MT+中观察到的视觉驱动的活动不足以介导有意识的视觉。更令人惊讶的是，视觉驱动的活动在相应的区域V1和早期的纹外区，包括hV 5/MT+并不能保证视觉感知的患者组后膝状体病变，我们检查。这表明，视觉活动模式在视觉区域的精细协调可能是视觉皮层损伤后视觉感知是否持续的重要决定因素。
Damage to the primary visual cortex (V1) leads to a visual field loss (scotoma) in the retinotopically corresponding part of the visual field. Nonetheless, a small amount of residual visual sensitivity persists within the blind field. This residual capacity has been linked to activity observed in the middle temporal area complex (V5/MT+). However, it remains unknown whether the organization of hV5/MT+ changes following early visual cortical lesions. We studied the organization of area hV5/MT+ of five patients with dense homonymous defects in a quadrant of the visual field as a result of partial V1+ or optic radiation lesions. To do so, we developed a new method, which models the boundaries of population receptive fields directly from the BOLD signal of each voxel in the visual cortex. We found responses in hV5/MT+ arising inside the scotoma for all patients and identified two possible sources of activation: 1) responses might originate from partially lesioned parts of area V1 corresponding to the scotoma, and 2) responses can also originate independent of area V1 input suggesting the existence of functional V1-bypassing pathways. Apparently, visually driven activity observed in hV5/MT+ is not sufficient to mediate conscious vision. More surprisingly, visually driven activity in corresponding regions of V1 and early extrastriate areas including hV5/MT+ did not guarantee visual perception in the group of patients with post-geniculate lesions that we examined. This suggests that the fine coordination of visual activity patterns across visual areas may be an important determinant of whether visual perception persists following visual cortical lesions.
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影响因子：
2.6
作者：
Bridge H;Hicks SL;Xie J;Okell TW;Mannan S;Alexander I;Cowey A;Kennard C
通讯作者：
Kennard C
影响因子：
11
作者：
Henriksson, L.;Raninen, A.;Vanni, S.
通讯作者：
Vanni, S.
影响因子：
14.5
作者：
HORTON, JC;HOYT, WF
通讯作者：
HOYT, WF
DOI：
10.1093/brain/awu328
发表时间：
2015-01
期刊：
Brain : a journal of neurology
影响因子：
--
作者：
Ajina S;Kennard C;Rees G;Bridge H
通讯作者：
Bridge H
影响因子：
3.7
作者：
Haak KV;Cornelissen FW;Morland AB
通讯作者：
Morland AB