Vision, Attention and Eye Movements at the Scale of the Foveola

项目摘要 人类依靠视网膜小凹进行探索，小凹是视网膜上锥细胞最密集的区域 高分辨率的视觉场景。尽管小凹只覆盖了视野的一小部分- 大约一个满月的大小，对这个地区的破坏对大多数人来说都是毁灭性的后果。 视觉活动。然而，主要由于技术挑战，人们对这些机制知之甚少。 以及人类获得高视力的感觉运动策略。 研究中央凹功能的一个主要困难来自于需要精细地控制视网膜刺激。在 由于不确定性，这种尺度，无论是将刺激放置还是保持在期望的偏心率都是困难的， 在定位注视中心（通常与小凹本身一样大）方面，并且由于连续的视网膜 由固定眼球运动引起的运动，缓慢的眼球漂移和人类不断进行的小扫视， 表演。PI和她的同事们最近绕过了这些限制，开发了新的方法 在注视的中心映射视觉功能。他们的研究表明， 在这个尺度上，注意力和眼球运动都受到精确控制。 这些先前的发现提出了一个基本假设：高敏锐度视力不会自动跟随 但这是视觉，运动， 和注意力成分，它们密切合作，顺序地提取精细的空间信息， 中央凹区本项目旨在调查这一假设，在三个密切相关的目标， 我们将研究注意力在高敏锐度视觉（目标1）中的作用，它是如何被微扫视（目标1）调节的 3），以及注意力和微眼跳如何处理精细模式的视觉处理限制（目标2）。 具体来说，在目标1中，我们将建立在我们以前关于精细控制自愿注意力的工作基础上， 小凹和研究这种现象的空间分辨率，其时间动态，以及它是否延伸 无意识的注意力。在目标2中，我们将绘制整个中央凹空间的视觉敏锐度，并检查视觉 在小凹内敏锐度和拥挤度不同。在目标3中，我们将研究mi的准确度和精密度。 交叉游戏，它们对缓解敏锐度和拥挤的生理限制的贡献，以及它们之间的联系 注意力的控制。视觉，注意力和眼动的相互作用将被研究- 不仅在一般意义上（观察员的平均结果），而且在个人层面上， 注意力和运动控制的程度是否存在协变，后者是否与特异质有关 敏锐度的差异。我们的主要假设是，精细的空间视觉是感觉运动相互作用的结果 有几个重要的后果。它提出了一种可能性，即注意力和固定的次优控制， 常规的眼球运动可能导致高敏锐度损伤。这项研究可能会为视觉 对眼球运动和注意力进行精细控制的康复程序。

PROJECT SUMMARY Humans rely on the foveola, the region of the retina where cones are most densely packed, for exploring the visual scene at high resolution. Although the foveola only covers a tiny portion of the visual field— approximately the size of a full moon—, damage to this area has devastating consequences for most daily visual activities. Yet, primarily as a consequence of technical challenges, little is known about the mechanisms of foveal vision and the sensorimotor strategies by which humans achieve high visual acuity. A major difficulty in studying foveal functions comes from the need to finely control retinal stimulation. At this scale, both placing and maintaining a stimulus at a desired eccentricity is difficult, because of uncertainty in localizing the center of gaze (typically as large as the foveola itself), and because of the continual retinal motion caused by fixational eye movements, the slow eye drifts and small saccades that humans continually perform. The PI and her coworkers have recently circumvented these limitations and developed new methods for mapping visual functions at the very center of gaze. Their research has shown that pattern vision varies sharply across the foveola, and that both attention and eye movements are precisely controlled at this scale. These previous findings raise a fundamental hypothesis: high acuity vision does not follow automatically from placing the stimulus on the foveola, but it is the outcome of an orchestrated synergy of visual, motor, and attentional components, which closely cooperate to sequentially extract fine spatial information from the foveal region. This project is designed to investigate this hypothesis, in three strongly inter-connected aims, we will examine the role of attention in high acuity vision (Aim 1), how it is modulated by microsaccades (Aim 3), and how both attention and microsaccades deal with limits in visual processing of fine patterns (Aim 2). Specifically, in Aim 1, we will build upon our previous work on the fine control of voluntary attention within the foveola and study the spatial resolution of this phenomenon, its temporal dynamics, and whether it extends to involuntary attention. In Aim 2, we will map visual acuity across the foveal space and examine how visual acuity and crowding vary within the foveola. In Aim 3, we will investigate the accuracy and precision of mi- crosaccades, their contributions to alleviating physiological limitations in acuity and crowding, and their links to attentional control within the foveola. The interplay of vision, attention, and oculomotor activity will be stud- ied not just in general terms (average results across observers) but also at the individual level, to determine whether the degree of attentional and motor control covary and whether the latter is linked to idiosyncratic differences in acuity. Our main hypothesis that fine spatial vision is the outcome of a sensorimotor interaction bears several important consequences. It raises the possibility that sub-optimal control of attention and fixa- tional eye movements may contribute to high acuity impairments. This research may open the way for visual rehabilitation procedures that act on the fine control of eye movements and attention.