An integrated model of fixational eye movements and microsaccades.
An integrated model of fixational eye movements and microsaccades.
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DOI：
10.1073/pnas.1102730108
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发表时间：
2011-09-27
影响因子：
11.1
通讯作者：
Pikovsky, Arkady
中科院分区：
文献类型：
--
作者：
Engbert, Ralf;Mergenthaler, Konstantin;Pikovsky, Arkady
当我们注视一个静止的目标时，我们的眼睛会不由自主地产生微小的（或固定的）眼球运动。这些注视性眼球运动被分类为慢分量（生理漂移、震颤）和微扫视，其代表快速、小幅度的运动。在这里，我们提出了一个综合的数学模型，用于生成缓慢的注视眼球运动和微扫视。该模型是基于自回避的随机游动的概念，在一个潜在的，一个过程驱动的一个自我生成的激活字段。自我回避行走在短时间尺度上产生持续的运动，而在较长的时间尺度上，潜在的产生反持续运动，使眼睛接近预期的固定位置。我们介绍微眼跳作为快速运动触发的关键激活值。因此，缓慢运动和微扫视都遵循相同的运动规律;即，运动由自生激活场驱动。因此，该模型有助于一个统一的解释，为什么它一直是一个长期存在的问题，以分离缓慢的运动和微扫视相对于他们的运动产生的原则。我们的结论是，一个自我避免的随机行走的概念捕捉的基本属性的注视眼球运动，并提供了一个连贯的理论框架，两个生理上不同的运动类型。
When we fixate a stationary target, our eyes generate miniature (or fixational) eye movements involuntarily. These fixational eye movements are classified as slow components (physiological drift, tremor) and microsaccades, which represent rapid, small-amplitude movements. Here we propose an integrated mathematical model for the generation of slow fixational eye movements and microsaccades. The model is based on the concept of self-avoiding random walks in a potential, a process driven by a self-generated activation field. The self-avoiding walk generates persistent movements on a short timescale, whereas, on a longer timescale, the potential produces antipersistent motions that keep the eye close to an intended fixation position. We introduce microsaccades as fast movements triggered by critical activation values. As a consequence, both slow movements and microsaccades follow the same law of motion; i.e., movements are driven by the self-generated activation field. Thus, the model contributes a unified explanation of why it has been a long-standing problem to separate slow movements and microsaccades with respect to their motion-generating principles. We conclude that the concept of a self-avoiding random walk captures fundamental properties of fixational eye movements and provides a coherent theoretical framework for two physiologically distinct movement types.