Interocular Suppression and Selective Attention in Amblyopia

 描述(申请人提供)：弱视(懒眼)，一只眼睛的视力丧失，无法通过眼镜矫正，是全球单眼视力丧失的最常见原因，影响3%-5%的人口。除了视力丧失外，很大比例的弱视患者缺乏双眼功能和深度知觉。视力和深度知觉的综合丧失对弱视患者的生活质量有重大影响。标准的临床治疗方法是对非弱视的同伴眼进行遮盖，以促进儿童弱视眼的使用。成年人通常不接受治疗，因为弱视一直被认为是成年人无法治疗的。遮盖疗法的成功率在60%到80%之间，治疗后20%到25%的复发，留下大约三分之一的弱视儿童持续到成年。这个项目试图了解目前治疗方法的失败，并为那些对传统疗法反应不佳的弱视患者提出替代疗法。我们认为视觉抑制是弱视视力丧失的根本因素，是治疗的一大障碍。我们认为弱视的视觉抑制可能是一种长期注意忽视的形式，学习照顾弱视眼睛可能会克服这种忽视并改善弱视眼睛的视觉功能。为了验证这一假设，Aim 1将检查有和没有残留双眼功能的弱视患者的皮质抑制，因为这两组患者的治疗结果不同。非双眼弱视更难治疗，而且在治疗后往往会消退。目标2将测量弱视患者选择性视觉注意的强度和潜伏期，并将这些结果与 目标1中的抑制测量。目标3将调查弱视眼睛中操纵注意力是否可以调节皮质抑制。目标4将验证这样的假设，即通过训练具有高注意要求任务的弱视眼可以缓解抑制并改善视觉功能。我们将使用常规知觉学习任务(低注意要求任务)和高注意要求任务来训练弱视个体。我们将使用视觉心理物理学结合频率标记源定位脑电测量来跟踪和评估训练期间的视觉功能(敏锐度和立体视)、抑制深度和注意力调节。从这项研究中获得的知识将有助于更广泛地了解视觉抑制的神经基础和弱视的发展。我们的结果将阐明弱视治疗为什么经常失败，并将表明更有效的治疗策略，特别是对那些对传统治疗反应不佳的人。

 DESCRIPTION (provided by applicant): Amblyopia (`lazy eye'), the loss of visual acuity in one eye that cannot be corrected by glasses, is the most common cause of monocular vision loss worldwide and affects 3-5% of population. In addition to the acuity loss, a high proportion of amblyopic patients lack binocular function and depth perception. The combined loss of acuity and depth perception has a significant impact on the quality of life in amblyopes. The standard clinical treatment is to patch the non-amblyopic fellow eye to promote the use of the amblyopic eye in children. Adults are usually not treated, because amblyopia has long been considered untreatable in adults. With occlusion therapy, the success rate ranges from 60% to 80% with 20-25% recurrence following treatment, leaving about one third of affected children with amblyopia that persists into adulthood. This project seeks to understand the failure of current treatment approaches and proposes alternative therapies for those amblyopic patients who do not respond well to the conventional regimen. We believe that visual suppression, the fundamental factor in amblyopic visual loss, is a great barrier to treatment. We propose that visual suppression in amblyopia may be a form of long-term attentional neglect and that learning to attend to the amblyopic eye may overcome this neglect and improve visual function in the amblyopic eye. To test this hypothesis, Aim 1 will examine cortical suppression in amblyopic individuals with and without residual binocular function, because these two groups of patients have different treatment outcomes. Non-binocular amblyopes are more difficult to treat and often regress following treatment. Aim 2 will measure both the strength and the latency of selective visual attention in individuals with amblyopia, and will correlate these results with the suppression measurements in Aim 1. Aim 3 will investigate whether manipulating attention in the amblyopic eye can modulate cortical suppression. Aim 4 will test the hypothesis that suppression can be alleviated and visual function will be improved by training the amblyopic eye with high attention-demand tasks. We will use both conventional perceptual learning tasks (low attention-demand tasks) and high attention-demand tasks to train individuals with amblyopia. We will track and evaluate visual function (acuity and stereopsis), depth of suppression, and attentional modulation during training by using visual psychophysics coupled to frequency-tagged source-localized EEG measurements. The knowledge gained from this study will contribute significantly to a broader understanding of the neural basis of visual suppression and the development of amblyopia. Our results will shed light on why amblyopic therapy often fails, and will indicate more efficient treatment strategies, especially for those who do not response well to conventional treatment.