Cortical processing of global form, motion and biological motion under low light levels
Cortical processing of global form, motion and biological motion under low light levels
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DOI：
10.1016/j.visres.2016.01.008
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发表时间：
2016-04-01
期刊：
影响因子：
1.8
通讯作者：
Nardini, Marko
中科院分区：
文献类型：
--
作者：
Burton, Eliza;Wattam-Bell, John;Nardini, Marko
视杆细胞和视锥细胞营养不良的潜在治疗方法的进展增加了了解视杆细胞和视锥细胞对更高层次皮质视觉的贡献的必要性。我们测量的形式，运动和生物运动相干阈值和脑电图稳态视觉诱发电位（SSVEP）的反应范围从明视到暗视的光照条件下。弱光增加阈值的所有三种刺激，但是，全球形式的阈值相对受损比全球运动或生物运动。SSVEP响应相干的全球形式和运动减少在低光，运动反应显示了从中线到更多的横向位置的地形变化。对比敏感度测量证实，基本的视觉处理也受到弱光的影响。然而，对比度敏感度函数（CSF）的减少实现的光学模糊的比较表明，这些都不足以解释结果的模式，虽然杆系统的时间属性也可能发挥作用。总的来说，在纹外区的中级处理是不同的光水平的影响，在低水平的时空敏感性方面无法解释的方式。暗视运动SSVEP反应的地形变化可能反映了V1和纹外区之间的抑制反馈机制的变化或减少对视觉皮层的输入。这些结果提供了深入了解更高层次的皮层视觉是如何正常组织的情况下，锥输入，并提供了一个基础与锥营养不良的患者进行比较，治疗前后旨在恢复锥功能。(C)2016爱思唯尔有限公司版权所有
Advances in potential treatments for rod and cone dystrophies have increased the need to understand the contributions of rods and cones to higher-level cortical vision. We measured form, motion and biological motion coherence thresholds and EEG steady-state visual evoked potentials (SSVEP) responses under light conditions ranging from photopic to scotopic. Low light increased thresholds for all three kinds of stimuli; however, global form thresholds were relatively more impaired than those for global motion or biological motion. SSVEP responses to coherent global form and motion were reduced in low light, and motion responses showed a shift in topography from the midline to more lateral locations. Contrast sensitivity measures confirmed that basic visual processing was also affected by low light. However, comparison with contrast sensitivity function (CSF) reductions achieved by optical blur indicated that these were insufficient to explain the pattern of results, although the temporal properties of the rod system may also play a role. Overall, mid-level processing in extra-striate areas is differentially affected by light level, in ways that cannot be explained in terms of low-level spatiotemporal sensitivity. A topographical shift in scotopic motion SSVEP responses may reflect either changes to inhibitory feedback mechanisms between V1 and extra-striate regions or a reduction of input to the visual cortex. These results provide insight into how higher-level cortical vision is normally organised in absence of cone input, and provide a basis for comparison with patients with cone dystrophies, before and after treatments aiming to restore cone function. (C) 2016 Elsevier Ltd. All rights reserved.