Amblyopic deficits in the timing and strength of visual cortical responses to faces
Amblyopic deficits in the timing and strength of visual cortical responses to faces
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DOI：
10.1016/j.cortex.2012.03.021
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发表时间：
2013-04-01
期刊：
影响因子：
3.6
通讯作者：
Vidnyanszky, Zoltan
中科院分区：
文献类型：
--
作者：
Banko, Eva M.;Koertvelyes, Judit;Vidnyanszky, Zoltan
行为学研究表明，弱视患者的物体视觉受损。然而，人类的神经生理学研究主要集中在视觉皮层加工的早期阶段的弱视效应，而对后来的、特定对象的神经加工缺陷的问题没有进行探索。通过测量事件相关电位（ERPs）对中央凹面部刺激的影响，我们表征了弱视对N170分量的影响，反映了更高水平的结构性面部加工。单试验分析显示，与斜视组和屈光参差组相比，弱视组ERP成分的潜伏期增加，变化更大。此外，相对于右半球的早期P1成分，N170在右半球上有额外的延迟，而在另一只眼睛中没有，这表明弱视中面部特异性皮层反应的进化较慢。另一方面，单次试验N170峰振幅在弱视和同眼之间的分布仅在斜视患者中存在差异，而在屈光参差患者中无差异。此外，弱视N170潜伏期增加与视敏度和注视稳定性的眼间差异相关，而振幅降低与眼间差异无关。我们发现在弱视刺激和同侧眼之间的预期神经振荡没有差异，这意味着刺激驱动的视觉皮层反应产生的神经过程损伤可能是观察到的弱视效应背后的主要原因。这些发现提供了证据，证明早期视觉体验的弱视破坏会导致更高水平的面部特异性视觉皮层反应的强度和时间缺陷，反映在N170成分中。(C) 2012 Elsevier Ltd.版权所有。
Behavioral research revealed that object vision is impaired in amblyopia. Nevertheless, neurophysiological research in humans has focused on the amblyopic effects at the earliest stage of visual cortical processing, leaving the question of later, object-specific neural processing deficits unexplored. By measuring event-related potentials (ERPs) to foveal face stimuli we characterized the amblyopic effects on the N170 component, reflecting higher-level structural face processing. Single trial analysis revealed that latencies of the ERP components increased and were more variable in the amblyopic eye compared to the fellow eye both in strabismic and anisometropic patent groups. Moreover, there was an additional delay of N170 relative to the early P1 component over the right hemisphere, which was absent in the fellow eye, suggesting a slower evolution of face specific cortical responses in amblyopia. On the other hand, distribution of single trial N170 peak amplitudes differed between the amblyopic and fellow eye only in the strabismic but not in the anisometropic patients. Furthermore, the amblyopic N170 latency increment but not the amplitude reduction correlated with the interocular differences in visual acuity and fixation stability. We found no difference in the anticipatory neural oscillations between stimulation of the amblyopic and the fellow eye implying that impairment of the neural processes underlying generation of stimulus-driven visual cortical responses might be the primary reason behind the observed amblyopic effects. These findings provide evidence that amblyopic disruption of early visual experience leads to deficits in the strength and timing of higher-level, face specific visual cortical responses, reflected in the N170 component. (C) 2012 Elsevier Ltd. All rights reserved.