Département de neurophysiologie clinique, hôpital de la Salpêtrière, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France.
Rev Neurol (Paris). 2012 Oct;168(10):734-40. doi: 10.1016/j.neurol.2012.07.016. Epub 2012 Sep 12.
Saccades allow object of interest that are perceived by the peripheral retina to be displayed on the fovea, a small central retinal area of maximum visual accuracy. Saccades may be generated under a large variety of circumstances, from reflexive like saccades (e.g. towards a threatening visual cue) to highly volitional saccades (e.g. towards the memorized location of a no longer present visual cue). These different contexts correspond to different complexities of decision-making processes and, on a behavioral aspect, to saccades with different latencies, and to the involvement of different cortical areas. However, whatever their type, saccades need to be fast, in order to avoid any persaccadic visual blur, and accurate since the fovea represents less than 1° of visual angle. This combination of accuracy and velocity is achieved thanks to a collaboration of brainstem and cerebellar oculomotor structures. The basic neural structures involved in these processes are reviewed, a special emphasis being given to clinically relevant mechanisms.
扫视使被周边视网膜感知到的感兴趣物体能够呈现在中央视网膜的一个小区域——即黄斑，这是一个具有最大视觉准确性的区域。扫视可以在各种情况下产生，从反射性扫视（例如朝向一个有威胁的视觉提示）到高度自主的扫视（例如朝向记忆中不再存在的视觉提示的位置）。这些不同的情境对应于不同复杂程度的决策过程，从行为方面来看，对应于具有不同潜伏期的扫视，以及涉及不同的皮质区域。然而，无论其类型如何，扫视都需要快速，以避免任何扫视后视觉模糊，并且需要准确，因为黄斑代表的视角不到 1 度。这种准确性和速度的结合是通过脑干和小脑眼球运动结构的协作来实现的。本文回顾了这些过程中涉及的基本神经结构，特别强调了与临床相关的机制。
