Visual Perception in Visual Snow Syndrome

项目总结/摘要 视觉雪综合征（VSS）是一种严重但知之甚少的视觉障碍，其特征是持续的 感觉到斑点在整个视野中闪烁，类似于电视上的雪。VSS估计 患病率为1.4-3.3%，通常伴有其他症状，如明显的后像 （复视症）、夜间视力差、内视现象和恐光症（光敏感性）。这些症状使 像阅读和驾驶这样的任务特别困难。虽然以前的研究集中在识别 常见症状和合并症，尚未确定有效的治疗方法，潜在的机制 这种疾病仍然是未知的，视觉感知的定量评估仍然很少。拟议 研究试图通过测量视觉表现的差异来解决这些知识差距， 将神经处理与一系列完善的心理物理和成像范例相关联。到 在VSS中提供感知和视觉处理的定量测量，我们将评估（1）对比敏感度， (2)与正常视力对照组相比，VSS患者的空间背景和（3）时间背景感知 通过一系列基本的心理物理和高场（7 T）功能磁共振成像， （功能磁共振成像）实验。这些实验将帮助我们了解VSS患者如何感知和处理 对比度，这是与日常视觉表现相关的视觉功能的重要指标 任务此外，拟议的研究将解决空间和时间背景如何改变， VSS-以前但稀疏的研究表明，空间和时间背景可能会改变VSS，但 需要更多的参与者和强有力的神经活动测量的进一步证据， 研究视觉背景处理的潜在差异。关键是，我们还将提供高分辨率的7 T 功能磁共振成像测量视觉任务中皮层反应以研究增益控制的潜在差异 整个视觉系统。拟议的视觉感知评估和相关测量 的神经加工在VSS是必要的，以更好地表征这种疾病，并将有助于制定假设 关于VSS的机制。

Project Summary/Abstract Visual Snow Syndrome (VSS) is a serious but poorly understood visual disorder characterized by the persistent perception of specks flickering across the entire visual field, akin to television snow. VSS has an estimated prevalence of 1.4-3.3% and is often accompanied by additional symptoms such as prominent afterimages (palinopsia), poor night vision, entoptic phenomena, and photophobia (light sensitivity). These symptoms make tasks like reading and driving particularly difficult. While previous research has focused on identifying the common symptoms and comorbidities, effective treatments have not been identified, the mechanisms underlying the disorder are still unknown, and quantitative assessments of visual perception remain sparse. The proposed research seeks to address these knowledge gaps by measuring differences in visual performance and associated neural processing with a series of well-established psychophysical and imaging paradigms. To provide quantitative measures of perception and visual processing in VSS, we will assess (1) contrast sensitivity, (2) spatial context, and (3) temporal context perception in people with VSS compared to normally sighted controls through a series of fundamental psychophysical and high field (7T) functional magnetic resonance imaging (fMRI) experiments. These experiments will help us understand how people with VSS perceive and process contrast, which is an important measure of visual function that is related to performance on every-day visual tasks. Additionally, the proposed research will address how both spatial and temporal context are altered in VSS—previous but sparse research suggests that both spatial and temporal context may be altered in VSS, but further evidence with both larger numbers of participants and robust measures of neural activity are required to investigate potential differences in visual context processing. Critically, we will also provide high resolution 7T fMRI measures of cortical responses during visual tasks to investigate potential differences in gain control throughout the visual system. The proposed assessment of visual perception and accompanying measurements of neural processing in VSS are necessary to better characterize this disorder, and will help formulate hypotheses about mechanisms underlying VSS.