Cognitive and cortical mechanisms of trans-saccadic motion perception

我的研究项目调查了一种基本的日常有意识视觉体验的潜在机制：尽管每次我们移动眼睛时，视觉场景中物体的位置发生了戏剧性的变化，但我们对稳定和连续的视觉世界的感知。我们使用被称为扫视的快速眼球运动扫描周围环境。我们通常每秒大约进行3-5次扫视。在每一次扫视中，整个世界的图像在我们的视网膜上移动，我们周围的物体移动到不同的视网膜位置。然而，这些物体并不是随着我们眼睛的移动而跳来跳去的，它们通常被认为在空间上是稳定的。这是所谓的跨眼跳知觉中知觉连续性的一个例子，表明视觉系统有机制通过考虑眼跳过程中凝视的变化来跟踪物体在空间中的位置。大多数关于跨眼跳知觉中知觉连续性的研究都集中在大脑如何跟踪静态视觉刺激在场景中的位置。但是，像我们在现实世界中所经历的那样，在带有移动对象的动态场景中会发生什么？例如，在开车时，我们经常会进行一系列扫视，以观察其他车辆或行人在我们的视野中移动。为了有效地与它们互动，我们的大脑必须将它们的运动从一眼整合到另一眼，以感知眼跳过程中持续的空间运动。本研究的目的是为了更全面地了解跨跳物体运动跟踪的认知机制和大脑皮层机制。在拟议的研究计划中，参与者将接受各种不同的视觉运动判断任务的测试，其中一些任务包括一种名为经颅磁刺激的非侵入性大脑刺激，以检查以下问题：1)与环境线索相比，大脑在多大程度和什么条件下依赖眼睛自身运动的内部信息来跟踪物体在扫视中的运动？2)我们可以跟踪多少物体的扫视？3)在推断的运动范式中，我们如何准确地对运动物体的未来位置做出空间判断？4)在编程眼动时，不同的大脑区域在多大程度上参与记忆或视觉运动处理在跨眼跳运动跟踪中起作用吗？这一研究项目的发现将对当前关于眼球运动中知觉连续性的理论产生重要影响，并为基本有意识视觉体验的潜在机制提供新的见解。

My research program investigates the underlying mechanisms of a fundamental everyday conscious visual experience: the perception of a stable and continuous visual world despite dramatic changes to the location of objects in a visual scene every time we move our eyes. We scan our surroundings using rapid eye movements called saccades. We typically make about 3-5 saccades per second. During each saccade the entire image of the world shifts across our retina and objects in our surroundings shift to different retinal locations. However, rather than perceiving these objects as jumping around as our eyes move they are normally perceived as spatially stable in the world. This is an example of perceptual continuity in so-called trans-saccadic perception, and suggests that the visual system has mechanisms for keeping track of where objects are in space by taking into account the change in gaze during saccades. Most research on perceptual continuity in trans-saccadic perception has been focused on how the brain keeps track of the locations of static visual stimuli in a scene. But what happens in a dynamic scene with moving objects like what we experience in the real world? For example, when driving we often make a series of saccades to look at other vehicles or pedestrians moving about our visual field. To interact with them effectively, our brain has to integrate their motion from one glance to another to perceive continuous spatial motion over the saccade. The objective of this research program is to gain a more complete understanding of the cognitive and cortical mechanisms of trans-saccadic object motion tracking. In the proposed research program, participants will be tested in a variety of different visual motion judgement tasks, some including a form of non-invasive brain stimulation called transcranial magnetic stimulation, to examine the following questions: 1) To what extent and under what conditions does the brain rely on internal information of the eyes' own movements compared to environmental cues to keep track of an object's movements over a saccade? 2) How many objects can we track across saccades? 3) How accurately can we make spatial judgments of a moving object's future position over a saccade in a inferred motion paradigm? 4) To what extent do different brain areas involved in programming eye movements, memory, or visual motion processing play a role in trans-saccadic motion tracking? The findings from this research program will have important implications for current theories of perceptual continuity across eye movements and offer new insight into the underlying mechanisms of a fundamental conscious visual experience.