DISTINGUISHING VISUAL FIELD MAP CLUSTERS: A NEW PARADIGM

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 导言：传统的视野映射是在一系列视野位置对刺激进行对比。视野图估计确定每个皮质位置的最有效刺激位置。常规方法(A)不包括空白时段，因此不可能知道是否所有刺激都引起一些响应，以及(B)通过仅指示最有效刺激位置的单个变量来总结响应。我们介绍了一种新的刺激方案和时间序列建模，提供了关于大脑皮层视野敏感度的额外信息。 方法和讨论：通过插入零对比度(平均亮度)的时间段，对传统的扩环和旋转楔形对比刺激进行了改进。新的范式允许我们比较多个位置的对比度反应与零对比度刺激，并从反应时间进程估计局部皮质视野响应性的更好的空间模型。除了常规的傅立叶分析外，还使用一般的线性模型来估计响应分量。V1-V3内的皮层主要对刺激位置敏感。外侧和腹侧枕叶皮质对来自视野更大部分的刺激做出反应，但对刺激位置也很敏感。V1图和LO图之间的过渡特别独特，允许分离原本难以辨别的汇合中心凹区域。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: Conventional visual field mapping contrasts stimuli at a series of visual field locations. Visual field map estimates identify the most effective stimulus position at each cortical location. Conventional methods (a) do not include a blank period, so that it is impossible to know whether all stimuli cause some response, and (b) summarize responses by a single variable that indicates only the most effective stimulus location. We introduce a new stimulus protocol and time-series modeling that provide additional information about cortical visual field sensitivity. Methods and Discussion: Conventional expanding ring and rotating wedge contrast stimuli were modified by inserting a time period with zero contrast (mean-luminance). The new paradigm allows us to compare contrast responses at multiple locations with a zero contrast stimulus and estimate a better spatial model of the local cortical visual field responsivity from the response time course. Besides conventional Fourier analysis, the response components were estimated using a general linear model. Cortex within V1-V3 is predominantly sensitive to stimulus location. Lateral and ventral occipital cortex respond to stimuli from a much larger part of the visual field, but is also sensitive to stimulus location. The transition between V1 and LO maps is particularly distinctive, allowing segregation of the confluent foveal regions that are otherwise hard to discern.