CORTICAL REPRESENTATION OF THE VISUAL IMAGE

该项目的主要目标是整合来自 空间、时间、方向性和双目视域，派生自 对消色差刺激的反应，转化为基于生理的描述 V1感受野(R.F.‘S)，并使用这种多维评估来 描述V1不同层和亚层内的神经元。它 还提出了扩展基于高斯空间模型的差异性 R.F.结构以包括时间参数。 在最初的实验中，空间、空间频率和方位 V1神经元的调谐将在一系列时间调制上进行测量 经济刺激的影响。将获得完整的时空调谐函数 对于每个神经元，使用阈值跟踪方法。此外，回应- 将在选定的点处测量对比度函数 时空表面以获得对比度增益和 压缩对比度的非线性程度。在第二个系列中 实验、单目和双目调谐将被测量和比较， 使用正弦波栅刺激。分词陈述将被用来 确定不同空间阶段的双目交互、空间 频率和对比度。在一些实验中，视差敏感度 被测量。这项建议的第三部分是适用详细的 在空间、时间和双目领域的定量测量 对细胞进行分类并确定功能类的分布 无论是在不同的皮质层内还是跨不同的皮质层。它的目的是 专注于主要输出层，即第2+3、4b、5和6层 它们有明显的纹状或皮质下靶点。这些 实验将给出一个全面的性能描述 向特定的外走区提供传入输入的神经元 因此，从V1开始，这些区域可以获得的信息的限制。这个 R.F.之间的关系将对尺寸和偏心进行调查 视锥感光器的潜在密度。目的是为了获得 衡量当地的空间尺度，并检查是否有 局部空间尺度的差异，特别是在中央凹区域，可以 与锥体分布有关。 在许多形式的弱视中，弱视的表现严重中断。 空间和双目任务，人们认为初级神经 功能障碍的部位是纹状皮质。多维的 R.F.的定量描述。属性在定义以下内容时非常重要 不同类型电池在不同环境中的预期性能极限 成年猕猴V1中的蛋鸡，因此是基本的 影响儿童发育障碍的认识和治疗 中枢视觉通路。

The principal aims of this project are to integrate information from the spatial, temporal, directional and binocular domains, derived from responses to achromatic stimuli, into physiologically based descriptions of V1 receptive fields (r.f.'s) and to use this multidimensional assessment to characterize neurons within the different layers and sublayers of V1. It is also proposed to extend the difference of Gaussians based spatial model of r.f. structure to include temporal parameters. In initial experiments the spatial, spatial frequency and orientation tuning of V1 neurons will be measured over a range of temporal modulations of the stimulus. A full spatiotemporal tuning function will be obtained for each neuron using a threshold tracking method. In addition, response- contrast functions will be measured at selected points over the spatiotemporal surface to obtain estimates of the contrast gain and the extent of the compressive contrast non-linearity. In a second series of experiments, monocular and binocular tuning will be measured and compared, using sinewave grating stimuli. Dichoptic presentation will be used to determine binocular interaction at different spatial phases, spatial frequencies and contrasts. In some experiments, disparity sensitivity will be measured. The third part of this proposal is to apply the detailed quantitative measures in the spatial, temporal and binocular domains to categorize cells and determine the distribution of the functional classes both within and across different cortical layers. It is intended to concentrate on the major output layers, layers 2 + 3, 4b, 5 and 6 all of which have distinct extrastriate or sub-cortical targets. These experiments will give a comprehensive description of the properties of the neurons providing afferent input to specific extrastroate areas and therefore the limits of information available to these areas from V1. The relationship between r.f. size and eccentricity will be investigated along with the underlying density of cone photoreceptors. The aim is to obtain measures of local spatial scale as well as to examine whether any differences in local spatial scale, particularly in the foveal region, can be related to the cone distribution. In many forms of amblyopia there is a severe disruption of performance on spatial and binocular tasks, and it is thought that the primary neural locus of the disfunction is the striate cortex. The multidimensional quantitative description of r.f. properties will be important in defining the expected limits of performance of different cell types in different layers in V1 of the adult macaque and is therefore basic to the understanding and treatment of the developmental disorders affecting the central visual pathways.