Robinson D L, McClurkin J W
Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Rev Oculomot Res. 1989;3:337-60.
The data reviewed here suggest several relationships between the superior colliculus, pulvinar and saccadic eye movements. These will be summarized in a series of steps in the visual initiation of saccadic eye movements. Area Pdm of the pulvinar appears to be involved in visual spatial attention. As such it may participate in the earliest decisions to make an eye movement: the shift of attention. This function is suggested by the spatially selective enhancement seen in the activity of individual neurons and the effects of drug injections on attentional performance. The attentional function of area Pdm is probably accomplished in coordination with cortical area 7 and possibly other areas. The spatially non-selective enhancement found in PI and PL may precede or follow the enhancement in Pdm. The next oculomotor function may be played by the visual cells in the superficial layers of the colliculus. Here the enhancement effect appears to be related to target selection which is specifically used with saccadic eye movements. Lesions here lead to animals who are not easily distracted by peripheral events; they do not select saccade targets. Thus the visual regions of the superior colliculus and Pdm may provide separate initiatives to the saccadic system. Once the eye begins to move, there are many relations manifested in both brain areas. Many of the visual collicular cells and those in parts of the pulvinar are unresponsive to visual stimuli during eye movements. In the colliculus, this particular effect may function to minimize erroneous visual targets whereas in the pulvinar the process may be more important perceptually. Finally there is a population of cells in the pulvinar which discharge during and after saccadic eye movements. These cells may have a role in the termination of one attentional scan and the beginning of the next. The pathways through which these effects may be mediated are totally unclear. The visual signal from the superficial layers related to saccade initiation may impinge directly on the cells in the intermediate layers or may reach the oculomotor system through other pathways. The parts of the pulvinar which relate to visual spatial attention are interconnected with posterior parietal cortex and probably function in concert with that area. How those data get to the oculomotor system has yet to be determined. Since the pulvinar is extensively interconnected with the cortex, it is most likely through this route that eye movement information coming from the superior colliculus is brought to higher perceptual areas.(ABSTRACT TRUNCATED AT 400 WORDS)
此处回顾的数据表明上丘、丘脑枕与眼球的快速扫视运动之间存在多种关系。这些关系将在眼球快速扫视运动的视觉启动过程中按一系列步骤进行总结。丘脑枕的Pdm区似乎与视觉空间注意力有关。因此，它可能参与了做出眼球运动的最早决策：注意力的转移。单个神经元活动中所见的空间选择性增强以及药物注射对注意力表现的影响表明了这一功能。Pdm区的注意力功能可能是与皮层7区以及可能的其他区域协同完成的。在PI和PL区发现的空间非选择性增强可能先于或后于Pdm区的增强。下一个眼球运动功能可能由上丘表层的视觉细胞发挥。此处的增强效应似乎与目标选择有关，这在眼球快速扫视运动中被专门利用。此处受损会导致动物不易被周边事件分散注意力；它们不会选择扫视目标。因此，上丘和Pdm区的视觉区域可能为扫视系统提供不同的起始信号。一旦眼球开始运动，在这两个脑区都会表现出许多关系。许多视觉上丘细胞以及丘脑枕部分区域的细胞在眼球运动期间对视觉刺激无反应。在上丘，这种特殊效应可能起到将错误的视觉目标最小化的作用，而在丘脑枕，这个过程在感知方面可能更重要。最后，丘脑枕中有一群细胞在眼球快速扫视运动期间及之后放电。这些细胞可能在一次注意力扫描的终止和下一次扫描的开始中发挥作用。这些效应可能通过的途径完全不清楚。与扫视启动相关的来自表层的视觉信号可能直接作用于中层的细胞，或者可能通过其他途径到达眼球运动系统。与视觉空间注意力相关的丘脑枕部分与后顶叶皮层相互连接，可能与该区域协同发挥作用。这些数据如何到达眼球运动系统还有待确定。由于丘脑枕与皮层广泛相互连接，来自上丘的眼球运动信息很可能是通过这条途径被带到更高的感知区域。（摘要截选至400词）
