How Does Normalization Regulate Visual Competition?

项目总结/摘要 人类视觉系统如何调节相互竞争的感觉信息？流行的理论认为， 被称为分裂归一化的计算在控制神经竞争中起着关键作用。正常化 被认为是一种典型的神经计算，可能会驱动整个大脑的反应。有趣的是， 有证据表明，正常化的普遍作用依赖于对刺激的精确调整 特征，如方向和空间频率，但这种特征选择性的归一化性质， 令人惊讶的是，研究不足，特别是在人类身上。我们的长期目标是了解 支持人类视觉层次的视觉，并描述它们如何随着 选择性注意这项建议的目的是采用最先进的功能性神经影像技术 和分析，以阐明允许标准化控制人口的调谐特性 人类视觉皮层的反应，并了解正常化如何支持选择性注意。 我们通过首先描述早期视觉中归一化的选择性特性来解决这个问题。 大脑皮层在正常的、被动的、观看场景时的反应。然后，我们将评估模型的统一潜力， 分裂的正常化，研究正常化在调节竞争中的作用，通过空间- 定向和基于特征的注意力。通过揭示人类视觉中调谐归一化所扮演的角色， 皮质，这些研究将为诊断工具的开发提供必要的框架， 涉及中央视觉处理缺陷的临床疾病的治疗。

PROJECT SUMMARY/ABSTRACT How does the human visual system regulate competing sensory information? Prevailing theories propose that a computation known as divisive normalization plays a key role in governing neural competition. Normalization is considered a canonical neural computation, potentially driving responses throughout the brain. Interestingly, there is evidence to suggest that normalization’s pervasive role relies on an exquisite tuning to stimulus features, such as orientation and spatial frequency, but this feature-selective nature of normalization is surprisingly understudied, particularly in humans. Our long-term goal is to understand the neural mechanisms supporting vision across the visual hierarchy in humans, and to characterize how they flexibly change with selective attention. The aim of this proposal is to employ state-of-the-art functional neuroimaging techniques and analyses to shed light on the tuning characteristics that allow normalization to control population responses within human visual cortex, and to understand how normalization can support selective attention. We approach the problem by first characterizing the selective properties of normalization within early visual cortex during normal, passive, scene viewing. We will then assess the unifying potential of models based on divisive normalization, examining the role that normalization plays in regulating competition via spatially- directed and feature-based attention. By revealing the role played by tuned normalization within human visual cortex, these studies will provide the necessary framework for the development of diagnostic tools and treatments for clinical disorders that involve deficits in central visual processing.