Munoz D P, Corneil B D
Department of Physiology, Queen's University, Kingston, Ontario, Canada.
Exp Brain Res. 1995;103(1):168-73. doi: 10.1007/BF00241974.
We examined the processes controlling selective orientation, specifically the processes required for generating saccadic eye movements in humans. Before a saccadic eye movement can be initiated, active visual fixation must be disengaged from the current point of fixation and a new target selected. We investigated whether these neural processes occur independently or interactively by devising a simple, multimodal choice reaction task in which subjects were asked to direct their gaze away from a central visual fixation target to an eccentric visual target while ignoring a simultaneous auditory distractor. Subjects had more difficulty suppressing incorrect movements toward the distractor when the fixation target was extinguished prior to onset of the eccentric target than when the fixation target remained illuminated during eccentric target presentation. Subjects with the shortest saccadic reaction times produced the most incorrect movements. These results support a recent hypothesis suggesting that the processes of disengaging active visual fixation and selecting a new saccade target are interrelated and arise, at least in part, from a change of activity within the superior colliculus.
我们研究了控制选择性定向的过程，特别是在人类中产生眼球跳动所需的过程。在启动眼球跳动之前，必须解除对当前注视点的主动视觉注视，并选择一个新的目标。我们通过设计一个简单的多模态选择反应任务来研究这些神经过程是独立发生还是相互作用的，在该任务中，要求受试者将目光从中央视觉注视目标移开，转向一个偏心视觉目标，同时忽略一个同时出现的听觉干扰物。当注视目标在偏心目标出现之前熄灭时，受试者比在偏心目标呈现期间注视目标保持点亮时更难抑制向干扰物的错误运动。眼跳反应时间最短的受试者产生的错误运动最多。这些结果支持了最近的一个假设，即解除主动视觉注视和选择新的眼跳目标的过程是相互关联的，并且至少部分地源于上丘内活动的变化。
