Interocular Suppression and Selective Attention in Amblyopia

项目摘要 长期和慢性的视觉抑制非首选眼的视觉输入是一个关键因素 发展成弱视，或“懒眼”，以及治疗弱视的关键障碍。弱视是常见的 由眼睛不对齐(斜视)引起，一只眼因屈光不等导致慢性光学模糊 两只眼睛的屈光参差(屈光参差)，或儿童早期斜视和屈光参差的混合， 影响到全球约3%至5%的人口。我们的长期目标是了解如何以及在哪里 抑制发生在大脑中。我们认为选择性视觉注意在视觉抑制中起作用。 我们在当前提案中的假设是，选择性视觉注意会导致眼睛和大脑之间的竞争 通过选择性地促进首选眼的反应和抑制来调节眼间抑制 非首选眼沿视觉皮质层级的反应。为了检验我们的假设，我们将使用 测量弱视眼中有效的刺激线索是否减少抑制的心理物理学 弱视成人的分视与无效/中性线索的比较(目标1)。在目标2中，我们将 使用频率标记的脑电源成像以及感知眼球优势的行为测量 比较双眼竞争对弱视患者选择性注意和增加对比度的影响 感知和神经反应。我们将同时测量和比较沿线的神经活动 视知觉优势和抑制状态下成人双眼皮质层级 弱视和视力正常。这些测量将有助于确定：1)大脑如何以及在哪里受到抑制 弱视中的视觉冲突图像；2)如何通过增加 弱视眼睛的对比度输入改变了弱视眼睛信号的神经表示。 关注弱视眼睛对神经活动的影响是否与增加对比度类似 弱视眼。在目标3中，我们将使用频率标记脑电源成像和视觉 在多目标跟踪任务中测量皮质活动和行为表现的心理物理学 一只眼睛看到移动的目标，另一只眼睛看到移动的分心物体。这一目标将 综合表征：1)视觉注意是否通过选择性调节眼间抑制 促进来自首选眼的神经反应和抑制来自非首选眼的反应 沿着视觉皮质层级(目标3a)；2)注意调节是否存在差异 在时间动力学(目标3b)和注意资源方面，在正常视觉和弱视之间 可获得性由要跟踪的目标数目确定(目标3c)。拟议的研究将 系统研究视觉感知和神经关联潜在的眼间抑制 提供沿皮质的生理水平弱视患者视觉抑制的综合图像 等级和知觉层面。从我们计划的学习中获得的知识将帮助我们更好地 了解弱视抑制发生的方式和地点，将有助于确定治疗策略 弱视用的。

Project Summary Long-term and chronic visual suppression to the visual input from the non-preferred eye is a key factor in developing amblyopia, or “lazy eye”, as well as a critical barrier to treat amblyopia. Amblyopia is commonly caused by misalignment of the eyes (strabismus), chronic optical blur in one eye due to unequal refractive errors in two eyes (anisometropia), or a mixture of strabismus and anisometropia during early childhood, affecting about 3% to 5% of the population worldwide. Our long-term goal is to understand how and where suppression occurs in the brain. We propose that selective visual attention plays a role in visual suppression. Our hypothesis in the current proposal is that selective visual attention biases competition between eyes and modulates interocular suppression by selectively facilitating responses from the preferred eye and suppressing responses from the non-preferred eye along the visual cortical hierarchy. To test our hypothesis, we will use psychophysics to measure whether valid cueing of the stimulus in the amblyopic eye reduces suppression under dichoptic viewing in adults with amblyopia, compared with invalid/neutral cueing (Aim 1). In Aim 2, we will use frequency-tagged EEG source imaging along with behavioral measures of perceptual eye dominance during binocular rivalry to compare the effects of selective attention and increased contrast to the amblyopic eye on perception and neural responses. We will simultaneously measure and compare the neural activities along the cortical hierarchy of both eyes under the states of visual perceptual dominance and suppression in adults with amblyopia and normal vision. These measures will help determine: 1) how and where the brain suppresses visually conflicting images in amblyopia; 2) how an increase in bottom-up visual salience by increasing the contrast input to the amblyopic eye changes the neural representation of the amblyopic eye signal and 3) whether paying attention to the amblyopic eye has a similar effect on neural activity as increasing contrast to the amblyopic eye. In Aim 3, we will use frequency-tagged EEG source imaging coupled with visual psychophysics to measure cortical activity and behavioral performance during a multiple-object tracking task with moving targets presented to one eye and moving distractors presented to the other eye. This aim will comprehensively characterize: 1) whether visual attention modulates interocular suppression by selectively facilitating neural responses from the preferred eye and suppressing responses from the non-preferred eye along the visual cortical hierarchy (Aim 3a); 2) whether there are differences in attentional modulation between normal and amblyopic vision, in terms of temporal dynamics (Aim 3b) and attentional resource availability determined by the number of targets to be tracked (Aim 3c). The proposed studies will systematically investigate visual perception and neural correlates underlying interocular suppression to provide an integrated picture of visual suppression in amblyopia at physiological levels along the cortical hierarchy as well as perceptual levels. Knowledge gained from our planned studies would help us better understand how and where amblyopic suppression occurs and in turn, will help identify therapeutic strategies for amblyopia.