Cognitive and cortical mechanisms of trans-saccadic motion perception

我的研究项目调查了基本的日常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巨大变化，但对稳定和连续的视觉世界的感知。我们用快速的眼动扫描周围的环境。我们通常每秒进行3-5次扫视。在每次扫视过程中，整个世界的图像会在视网膜上移动，我们周围的物体也会移动到视网膜的不同位置。然而，当我们的眼睛移动时，这些物体并没有被认为是跳跃的，它们通常被认为是空间稳定的。这是所谓的跨扫视知觉中感知连续性的一个例子，并表明视觉系统具有通过考虑扫视期间凝视的变化来跟踪物体在空间中的位置的机制。大多数关于跨眼球知觉知觉连续性的研究都集中在大脑如何跟踪场景中静态视觉刺激的位置。但是，在一个动态的场景中，移动的物体会发生什么，就像我们在现实世界中经历的那样？例如，当我们开车时，我们经常会做一系列的扫视，看看在我们视野范围内移动的其他车辆或行人。为了有效地与他们互动，我们的大脑必须整合他们的动作，从一个眼神到另一个眼神，以感知扫视过程中连续的空间运动。本研究计划的目的是为了更全面地了解跨眼跳物体运动跟踪的认知和皮层机制。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称为经颅磁刺激的非侵入性脑刺激形式，以检验以下问题：1)与环境线索相比，大脑在多大程度上和在什么条件下依赖于眼睛自身运动的内部信息来跟踪扫视过程中物体的运动？2)我们在扫视中可以跟踪多少个对象？3)在推断的运动范式中，我们对一个运动物体在扫视过程中的未来位置做出空间判断的准确性有多高？4)参与眼球运动编程、记忆或视觉运动处理的不同脑区在跨眼动追踪中发挥了多大的作用？该研究项目的发现将对当前的眼动知觉连续性理论产生重要影响，并为基本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.