Towards a unified theory of microsaccadic and saccadic function: determining the significance of microsaccades for perception, cognition, and oculomotor control

扫视眼球运动--在探索视觉场景时转移我们视线的眼球运动--扮演着对视觉感知至关重要的多个角色。它们将高兴趣目标带到我们视觉的中心，它们搜索并整合关于环境的一般信息，将每个视觉场景拼接在一起，它们纠正凝视错误，它们是引导我们注意力的主要机制。当我们在两次扫视之间凝视时，我们的眼睛仍然在不停地移动，产生了所谓的凝视眼球运动。关于凝视眼球运动对注视过程中可见性的影响、它们纠正注视错误的准确性以及它们与注意力和其他认知过程的关系，人们存在着分歧。这些争议大多集中在历史上归因于微扫视的主要作用--最大、最快的注视眼球运动--例如防止和恢复注视过程中的视力损失，以及纠正注视错误。研究人员将在人类观察者身上进行眼动实验和分析，以确定微眼跳对大范围刺激的可见性和凝视过程中眼动错误的纠正的影响。在视觉探索过程中，我们大约80%的时间是凝视，因此了解凝视眼动的知觉效应对于理解视觉至关重要。该项目旨在扩大微眼跳的范围，从具有单一或主要功能到在视觉中扮演多个非排他性角色，就像大型眼跳一样。因此，研究人员将着手确定微眼跳是否能恢复所有褪色刺激的可见性--或者只恢复一小部分刺激的可见性--并阐明微眼跳在纠正注视错误中的作用。此外，了解微眼跳作为刺激特征的函数如何影响可见度将改善视觉研究的解释，这些研究大多是在注视条件下进行的。最后，确定凝视位置错误后的微眼跳重新定位可能有助于工程师在设计显示器和程序时考虑这些影响，以提高操作设备的准确性。

Saccadic eye movements -- the eye movements that shift our gaze during exploration of a visual scene --play multiple roles that are critical to visual perception. They bring high-interest targets to the center of our vision, they search and integrate general information about the environment to stitch together each visual scene, they correct gaze errors, and they are a primary mechanism to direct our attention. When we fixate our gaze between saccades, our eyes nevertheless move constantly, producing so called fixational eye movements. There is disagreement about the impact of fixational eye movements on visibility during fixation, their accuracy in correcting fixation errors, and their relationship with attention and other cognitive processes. Most of these controversies focus on the main roles historically attributed to microsaccades -the largest and fastest fixational eye movement-, such as the prevention and restoration of vision loss during fixation and the correction of fixation errors. The investigators will conduct eye movement experiments and analyses in human observers so as to determine the effects of microsaccades on the visibility of a large range of stimuli and on the correction of oculomotor error during fixation.We fixate our gaze about 80% of the time during visual exploration, and so understanding the perceptual effects of fixational eye movements is critical to understanding vision. The project aims to widen the scope of microsaccades from having a single or primary function to playing multiple non-exclusive roles in vision, in the same fashion as large saccades do. As such, the investigators will set out to determine whether microsaccades restore the visibility of all faded stimuli -or only that of a narrow range of stimuli- and to elucidate the role of microsaccades in the correction of fixation error. Understanding how microsaccades affect visibility as a function of stimulus characteristics will moreover improve the interpretation of visual studies, most of which are conducted under fixation conditions. Finally, determining that microsaccades re-target fixation after gaze position errors may help engineers to account for these effects in the design of displays and procedures to improve accuracy when operating equipment.