Early parallel processing of visual spatial information and its subsequent convergence in the visual pathway

如果空间形式(例如条形)的内部在以下任何一个维度上与周围环境有足够的差异：亮度、颜色、运动、纹理、相对立体深度，则可以将其呈现为可见。在日常生活中，这些线索中的几个经常同时出现。我们早就知道，(1)对于亮度定义的形式，视觉处理的时间序列的早期阶段通过平行的形式检测机制来粗略地分析眼睛后面的图像，每个平行的形式检测机制对一系列对象的大小和方向选择性地敏感，以及(2)在大小和方向上刚刚可察觉的差异远远小于这些早期检测机制的带宽。我们发表的实验证据表明，这些刚刚可察觉的差异很小，因为它们是由早期检测机制中的相对活动决定的。我们发现，对于通过相对运动、纹理差异或相对深度呈现可见的空间形状，在方向、大小和形状上的明显差异令人惊讶地小得令人惊讶，三种形式的差异并不大。这项研究旨在发现(1)通过相对运动或纹理呈现的空间形式在大小、方向和形状上的显著差异是否也由相关类型的空间形式的检测机制之间的相对活动决定，以及(2)不同类型空间形式的大小、方向和形状的信息在视觉加工阶段之前被汇集的程度，在该阶段计算出大小、方向或形状的略可见的差异。我预计，拟议的研究将扩大目前对我们看到物体并将一个物体与另一个物体区分开来的能力的理解，这种新的理解将导致用于培训商业飞行员的飞行模拟器的视觉显示器设计的改进。

A spatial form (e.g. a bar) can be rendered visible if its interior differs sufficiently from its surroundings in any one of the following dimensions: brightness; colour; motion; texture; relative stereoscopic depth. In the everyday world several of these cues are often present simultaneously. It has long been known that (1) for brightness-defined form, an early stage in the temporal sequence of visual processing crudely analyzes the image at the back of the eye through parallel form detection mechanisms, each of which is selectively sensitive to a range of object sizes and orientations, and (2) that the just-noticeable difference in size and orientation is far smaller than the bandwidths of these early detection mechanisms.We published experimental evidence that these just-noticeable differences are small because they are determined by the relative activity across the early detection mechanisms.We have found that, for spatial form that is rendered visible by relative motion, or texture difference or relative depth, just-noticeable differences in orientation, size and shape are surprisingly small and not greatly different for the three kinds of form. The proposed research is to find (1) whether just noticeable differences in size, orientation and shape for spatial form that is rendered visible by relative motion or by texture are also determined by the relative activity across detection mechanisms for the relevant kind of spatial form, and (2) the extent to which information about size, orientation and shape for different kinds of spatial form is pooled before the visual processing stage at which a just-noticeable difference in size, orientation or shape is computed. I envisage that the proposed research will extend current understanding of our ability to see objects and to distinguish one object from another, and that this new understanding will lead to improvements in the design of visual displays in flight simulators used to train commercial pilots.