DISTINGUISHING VISUAL FIELD MAP CLUSTERS: A NEW PARADIGM

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。传统的视野映射是在一系列的视野位置对比刺激。视野图估计在每个皮质位置确定最有效的刺激位置。传统方法(a)不包括空白期，因此不可能知道是否所有刺激都会引起某种反应；(b)通过单一变量总结反应，该变量仅表明最有效的刺激位置。我们介绍了一种新的刺激方案和时间序列模型，提供了皮层视野敏感性的额外信息。方法与讨论：通过插入零对比度（平均亮度）的时间段，对传统的扩张环和旋转楔形对比度刺激进行改进。新范式允许我们在零对比刺激下比较多个位置的对比反应，并从反应时间过程中估计局部皮层视野反应的更好的空间模型。除了传统的傅立叶分析外，还使用一般线性模型估计响应分量。V1-V3皮层主要对刺激位置敏感。枕侧和枕侧皮层对来自视野更大区域的刺激作出反应，但对刺激的位置也很敏感。V1和LO图之间的转换特别独特，允许分离融合的中央凹区域，否则很难辨别。

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.