Visual Perception in Visual Snow Syndrome

项目摘要/摘要 视觉雪综合征(VSS)是一种严重但知之甚少的视觉障碍，其特征是持续性 整个视野中闪烁着斑点的感觉，类似于电视上的雪。VSS有一个估计 患病率为1.4-3.3%，通常伴有其他症状，如突出的后遗症 (复视)、夜间视力差、内视现象和畏光(光敏感)。这些症状使 像阅读和驾驶这样的任务特别困难。虽然之前的研究主要集中在确定 常见的症状和合并症，有效的治疗方法尚未确定，潜在的机制 这种障碍仍然未知，对视觉感知的定量评估仍然很少。建议数 研究试图通过测量视觉表现和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公认的心理物理和成像范例联系起来。至 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)空间背景；(3)VSS患者与正常视力对照的时间背景知觉 通过一系列基本的心理物理和高场(7T)功能磁共振成像 (FMRI)实验。这些实验将帮助我们了解VSS患者是如何感知和处理的 对比度，这是与日常视觉表现有关的视觉功能的重要衡量标准 任务。此外，拟议的研究将解决空间和时间背景如何在 VSS-先前但稀少的研究表明，VSS的空间和时间语境都可能改变，但 需要有更多参与者和神经活动稳健测量的进一步证据才能 研究视觉情境加工中的潜在差异。最重要的是，我们还将提供高分辨率7T 视觉任务中皮层反应的fMRI测量，以调查增益控制的潜在差异 在整个视觉系统中。建议的视觉感知和伴随测量的评估 对VSS的神经处理的研究是必要的，以更好地描述这种疾病，并将有助于形成假说 关于VSS背后的机制。

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.