Department of Psychology, The University of Alabama at Birmingham, Birmingham, Alabama, United States.
Department of Psychology, The University of California at Riverside, Riverside, California, United States.
Invest Ophthalmol Vis Sci. 2023 Jan 3;64(1):14. doi: 10.1167/iovs.64.1.14.
Individuals with central vision loss due to macular degeneration (MD) often spontaneously develop a preferred retinal locus (PRL) outside the area of retinal damage, which they use instead of the fovea. Those who develop a stable PRL are more successful at coping with their vision loss. However, it is unclear whether improvements in visual performance at the PRL are specific to that retinal location or are also observed in other parts of the retina. Perceptual learning literature suggests that the retinal specificity of these effects provides insight about the mechanisms involved. Better understanding of these mechanisms is necessary for the next generation of interventions and improved patient outcomes.
To address this, we trained participants with healthy vision to develop a trained retinal locus (TRL), analogous to the PRL in patients. We trained 24 participants on a visual search task using a gaze-contingent display to simulate a central scotoma.
Results showed retinotopically specific improvements in visual crowding only at the TRL; however, visual acuity improved in both the TRL and in an untrained retinal locus.
These results suggest that training with an artificial scotoma involves multiple mechanistic levels, some location-specific and some not, and that simulated scotoma training paradigms likely influence multiple mechanisms simultaneously. Eye movement analysis suggests that the non-retinotopic learning effects may be related to improvements in the capability to maintain a stable gaze during stimulus presentation. This work suggests that effective interventions promoting peripheral viewing may influence multiple mechanisms simultaneously.
由于黄斑变性 (MD) 导致中央视力丧失的个体通常会在视网膜损伤区域外自发形成一个首选视网膜位置 (PRL)，他们会用这个位置代替黄斑来使用。那些形成稳定 PRL 的人在应对视力丧失方面会更成功。然而，目前尚不清楚在 PRL 上的视觉表现改善是否仅针对该视网膜位置，还是也可以在视网膜的其他部位观察到。视觉学习文献表明，这些效果的视网膜特异性提供了关于所涉及机制的见解。更好地了解这些机制对于下一代干预措施和改善患者预后是必要的。
为了解决这个问题，我们训练了具有健康视力的参与者形成一个训练有素的视网膜位置 (TRL)，类似于患者的 PRL。我们使用注视相关显示在一项视觉搜索任务中对 24 名参与者进行了训练，以模拟中央暗点。
结果表明，仅在 TRL 处出现了视觉拥挤的视网膜特异性改善；然而，在 TRL 和未经训练的视网膜位置，视力都得到了改善。
这些结果表明，使用人工暗点进行训练涉及多个机制层面，有些是位置特异性的，有些则不是，并且模拟暗点训练范式可能会同时影响多个机制。眼球运动分析表明，非视网膜特异性学习效应可能与在刺激呈现期间维持稳定注视的能力的提高有关。这项工作表明，促进周边观察的有效干预措施可能会同时影响多个机制。
