Schall J D, Morel A, King D J, Bullier J
Department of Psychology, Vanderbilt University, Nashville, Tennessee 37240, USA.
J Neurosci. 1995 Jun;15(6):4464-87. doi: 10.1523/JNEUROSCI.15-06-04464.1995.
The primate visual system consists of at least two processing streams, one passing ventrally into temporal cortex that is responsible for object vision, and the other running dorsally into parietal cortex that is responsible for spatial vision. How information from these two streams is combined for perception and action is not understood. Visually guided eye movements require information about both feature identity and location, so we investigated the topographic organization of visual cortex connections with frontal eye field (FEF), the final stage of cortical processing for saccadic eye movements. Multiple anatomical tracers were placed either in parietal and temporal cortex or in different parts of FEF in individual macaque monkeys. Convergence from the dorsal and ventral processing streams occurred in lateral FEF but not in medial FEF. Certain extrastriate areas with retinotopic visual field organizations projected topographically onto FEF. The dorsal bank of the superior temporal sulcus projected to medial FEF; the ventral bank, to lateral FEF, and the fundus, throughout FEF. Thus, lateral FEF, which is responsible for generating short saccades, receives visual afferents from the foveal representation in retinotopically organized areas, from areas that represent central vision in inferotemporal cortex and from other areas having no retinotopic order. In contrast, medial FEF, which is responsible for generating longer saccades, is innervated by the peripheral representation of retinotopically organized areas, from areas that emphasize peripheral vision or are multimodal and from other areas that have no retinotopic order or are auditory.
灵长类动物的视觉系统至少由两条处理通路组成，一条通路向腹侧延伸至颞叶皮质，负责物体视觉，另一条通路向背侧延伸至顶叶皮质，负责空间视觉。目前尚不清楚这两条通路的信息是如何结合起来用于感知和行动的。视觉引导的眼球运动需要有关特征识别和位置的信息，因此我们研究了视觉皮质与额叶眼区（FEF）之间的拓扑组织连接，额叶眼区是眼球跳动皮质处理的最后阶段。在个体猕猴中，将多种解剖示踪剂分别置于顶叶和颞叶皮质或额叶眼区的不同部位。背侧和腹侧处理通路在额叶眼区外侧汇聚，但在内侧额叶眼区没有汇聚。某些具有视网膜拓扑视野组织的纹外区域在拓扑上投射到额叶眼区。颞上沟的背侧缘投射到内侧额叶眼区；腹侧缘投射到外侧额叶眼区，而颞上沟底部则投射到整个额叶眼区。因此，负责产生短扫视的外侧额叶眼区接收来自视网膜拓扑组织区域的中央凹表征、颞下皮质中代表中央视觉的区域以及其他没有视网膜拓扑顺序的区域的视觉传入。相比之下，负责产生长扫视的内侧额叶眼区则由视网膜拓扑组织区域的外周表征、强调外周视觉或多模态的区域以及其他没有视网膜拓扑顺序或为听觉区域的神经支配。
