Visual Motion Coherence Responses in Human Visual Cortex.
Visual Motion Coherence Responses in Human Visual Cortex.
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DOI：
10.3389/fnins.2022.719250
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发表时间：
2022
影响因子：
4.3
通讯作者：
Smirnakis SM
中科院分区：
文献类型：
--
作者：
Rina A;Papanikolaou A;Zong X;Papageorgiou DT;Keliris GA;Smirnakis SM
随机点运动图（RDKs）最近被用于训练有皮层暗斑的受试者进行运动方向识别，部分恢复视觉运动感知。为了研究视觉知觉的恢复，了解正常受试者和皮层暗瘤受试者的视觉区域对RDK刺激的反应是很重要的。正常受试者的研究表明，人体hV5/MT+区域的血氧水平依赖性（BOLD）反应单调而连贯地增加，与灵长类动物的电生理学研究基本一致。然而，在先前的研究中，RDK反应是在受试者进行固定时获得的，而不是在运动辨别条件下获得的。此外，BOLD反应是在均匀照明或静态点的基线条件下进行测量的，这可能会降低局部运动信号空间整合反应的特异性（运动相干性）。在这里，我们从无相干的基线RDK条件开始重新审视这个问题，从而分离出由于局部运动信号的空间积分而导致的BOLD响应成分。与之前的研究结果一致，我们发现当受试者在不执行动作辨别任务的情况下注视时，hV5/MT+区域的反应单调增加。相比之下，当受试者执行RDK运动方向识别任务时，hV5/MT+区域的反应保持平稳，作为运动一致性的函数，如果有的话，变化最小。对暗斑内呈现的rks进行运动方向辨别时，在皮质暗斑密集受试者的hV5/MT+区也出现了类似的反应模式。暗斑内的被动RDK表现没有引起显著的hV5/MT+反应。这些观察结果进一步揭示了视觉皮层反应如何作为运动一致性的功能，有助于为未来使用这些方法研究损伤后视觉系统恢复的研究奠定基础。
Random dot kinematograms (RDKs) have recently been used to train subjects with cortical scotomas to perform direction of motion discrimination, partially restoring visual motion perception. To study the recovery of visual perception, it is important to understand how visual areas in normal subjects and subjects with cortical scotomas respond to RDK stimuli. Studies in normal subjects have shown that blood oxygen level-dependent (BOLD) responses in human area hV5/MT+ increase monotonically with coherence, in general agreement with electrophysiology studies in primates. However, RDK responses in prior studies were obtained while the subject was performing fixation, not a motion discrimination condition. Furthermore, BOLD responses were gauged against a baseline condition of uniform illumination or static dots, potentially decreasing the specificity of responses for the spatial integration of local motion signals (motion coherence). Here, we revisit this question starting from a baseline RDK condition of no coherence, thereby isolating the component of BOLD response due specifically to the spatial integration of local motion signals. In agreement with prior studies, we found that responses in the area hV5/MT+ of healthy subjects were monotonically increasing when subjects fixated without performing a motion discrimination task. In contrast, when subjects were performing an RDK direction of motion discrimination task, responses in the area hV5/MT+ remained flat, changing minimally, if at all, as a function of motion coherence. A similar pattern of responses was seen in the area hV5/MT+ of subjects with dense cortical scotomas performing direction of motion discrimination for RDKs presented inside the scotoma. Passive RDK presentation within the scotoma elicited no significant hV5/MT+ responses. These observations shed further light on how visual cortex responses behave as a function of motion coherence, helping to prepare the ground for future studies using these methods to study visual system recovery after injury.
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影响因子：
3.7
作者：
Huxlin, KR;Pasternak, T
通讯作者：
Pasternak, T
影响因子：
2
作者：
Beer, J;Blakemore, C;Liotti, M
通讯作者：
Liotti, M
影响因子：
1.9
作者：
BRITTEN, KH;SHADLEN, MN;MOVSHON, JA
通讯作者：
MOVSHON, JA
影响因子：
2.6
作者：
Cavanaugh MR;Barbot A;Carrasco M;Huxlin KR
通讯作者：
Huxlin KR
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