Cerebral Mechanism of Visually Guided Eye Movements

我们试图揭示的作用，额眼场（FEF）的视觉引导的眼球运动的产生警觉猕猴。我们首先将FEF的范围定位为皮质内微刺激引起扫视眼球运动的皮质区。发现该区域仅限于弓状沟的前堤，向前延伸至皮质暴露表面。在这样定义的FEF，有地形组织的幅度电引起的眼跳。我们获得了类似的幅度和方向在所有深度的皮层轨迹扫视。当刺激不同的位点时，眼跳矢量特性发生系统性变化。在FEF的外侧部分引起小的扫视，而在内侧部分引起大的扫视。我们还通过记录视觉神经元研究了FEF的视觉输入。它们广泛存在于FEF中，并且它们再次被地形组织起来。在外侧部分，神经元在注视中心附近有小的感受野。内侧部的神经元在周边视野中有较大的感受野。然后，我们进一步研究了视觉输入和运动（扫视）输出之间的关系，在每个位点。眼跳使视线进入刺激前视觉感受野所占据的部分，表明视觉输入促进了眼跳的产生。考虑到这些结果与传入和传出神经结构的分化，我们假设，FEF在视觉对象触发的扫视产生中起着重要的作用。

We tried to reveal the role of the frontal eye field (FEF) in the generation of visually guided eye movements using alert macaque monkeys. We first localized the extent of the FEF as the cortical area in which intracortical microstimulation elicites saccadic eye movements. The area was found to be restricted in the anterior bank of the arcuate sulcus extending anteriorly to the cortical exposed surface. In thus defined FEF, there was topographic organization regarding the amplitude of the electrically elicited saccade. We obtained saccades with similar amplitude and direction in all depth of a cortical locus. When stimulating different loci, saccade vector properties changed systematically. A small saccade was elicited in the lateral portion of FEF, and a large one was in the medial portion. We also investigated the visual input to the FEF by recording visual neurons. They were diffusely present in the FEF, and they were again topographically organized. In the lateral portion, neurons had small receptive fields near the center of gaze. Neurons in the medial portion had large receptive fields in the peripheral visual field. Then, we further examined the relation between the visual input and the motor (saccadic) output in each locus. The saccade brought the visual line into a part where the visual receptive field had occupied before the stimulation, suggesting that the visual input facilitates the saccade generation. Considering these results together with differentiation in the afferent and efferent neural structures, we postulated that the FEF plays an important role in the generation of saccades triggered by a visual object.