Hess R F, Dakin S C
McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
Nature. 1997 Dec 11;390(6660):602-4. doi: 10.1038/37593.
Human foveal vision is subserved initially by groups of spatial, temporal and orientational 'filters', the outputs of which are combined to define perceptual objects. Although a great deal is known about the filtering properties of individual cortical cells, relatively little is known about the nature of this 'linking' process. One recent approach has shown that the process can be thought of in terms of an association field whose strength is determined conjointly by the orientation and distance of the object. Here we describe a fundamental difference in this feature-linking process in central and peripheral parts of the visual field, which provides insight into the ways that foveal and peripheral visual perception differ. In the fovea, performance can be explained only by intercellular linking operations whereas in the periphery intracellular filtering will suffice. This difference represents a substantial economy in cortical neuronal processing of peripheral visual information and may allow a recent theory of intercellular binding to be tested.
人类中央凹视觉最初由空间、时间和方向“滤波器”组来支持，这些滤波器的输出被组合起来以定义感知对象。尽管人们对单个皮质细胞的滤波特性了解很多，但对这种“连接”过程的本质却知之甚少。最近的一种方法表明，这个过程可以用一个关联场来解释，其强度由物体的方向和距离共同决定。在这里，我们描述了视野中央和周边部分在这种特征连接过程中的一个根本差异，这为理解中央凹视觉和周边视觉感知的不同方式提供了线索。在中央凹，只有通过细胞间连接操作才能解释其表现，而在周边，细胞内滤波就足够了。这种差异代表了皮质神经元对外周视觉信息处理的显著经济性，并且可能允许对一种最近的细胞间结合理论进行检验。
