Cortical encoding of unconscious visual information and its impact on behavior

项目概要/摘要 过于简短而不被注意到的刺激仍然可以促进对相同刺激的感知处理。 刺激几分钟后。尽管阈下启动现象已经被人们所知几十年了， 在没有意识的情况下，感觉信息是否以及如何在大脑中编码， 影响神经元回路中随后的感觉处理仍然是一个谜。我们将回答这些问题 问题的第一次通过检查，在单细胞分辨率，是否暴露于阈下刺激， 影响视觉皮层人群的知觉表现和信息编码。到 为了实现这一目标，我们将使用多电极记录猕猴早期和中期的单个单位活动。 水平的视觉皮层区域（V1和V4）和行为技术，以检查动态和编码， 阈下暴露期间和之后的神经元群体，以及它们对知觉表现的影响。要求1 将调查是否暴露于阈下刺激增加随后的知觉表现和 在人口活动中编码的信息量。我们的假设是阈下接触 当刺激随后出现在可检测性之上时的感知辨别性能 阈值，并增加从人口响应中提取的信息量。目标2将检查 阈下暴露后神经元和行为表现改善的机制。我们将 首先关注涉及光遗传失活的因果实验， 在阈下刺激呈现期间，视觉皮层中的神经元活动降低了阈下刺激的强度。 启动交叉相关分析随后将测试是否改进了网络和感知 阈下暴露后的表现与Hebbian机制一致，该机制是增加 功能连接，特别是对神经元激活的阈下刺激。目标3将审查 注意对阈下启动与神经元和知觉操作之间关系的影响。 我们将测试新的假设，即空间注意力降低阈下启动的功效-暴露于 无人看管的阈下刺激将与网络编码的更大改善相关， 感知性能相比，暴露出席的信息。相比之下，我们希望注意力 将增加阈上启动的强度，即，暴露于有意识的阈下刺激将是 与暴露于 无人值守的信息总之，我们提出的实验可能会促进我们的理解， 通过测试感官体验的极限及其与视觉皮层的关系， 感知，这将有助于开发有效的治疗方法来治疗低视力条件的大脑方面， 例如弱视、年龄相关性黄斑变性、糖尿病性视网膜病或中风。

PROJECT SUMMARY/ABSTRACT Stimuli presented too briefly to be noticed can nonetheless facilitate the perceptual processing of the same stimuli many minutes later. Whereas the phenomenon of subliminal priming has been known for decades, whether and how sensory information is encoded in the brain in the absence of awareness in a way that influences subsequent sensory processing across neuronal circuits remains a mystery. We will answer these questions for the first time by examining, at single cell resolution, whether exposure to subliminal stimuli influences perceptual performance and the coding of information across visual cortical populations. To accomplish this goal, we will use multiple-electrode recording of single-unit activity in macaque early and mid- level visual cortical areas (V1 and V4) and behavioral techniques to examine the dynamics and coding in neuronal populations during and after subliminal exposure, and their impact on perceptual performance. Aim 1 will investigate whether exposure to subliminal stimuli increases subsequent perceptual performance and the amount of information encoded in population activity. Our hypothesis is that subliminal exposure improves perceptual discrimination performance when stimuli are subsequently presented above the detectability threshold, and increases the amount of information extracted from the population response. Aim 2 will examine the mechanism of the improvement in neuronal and behavioral performance after subliminal exposure. We will first focus on causal experiments involving optogenetic inactivation which will test whether suppressing neuronal activity in visual cortex during the presentation of subliminal stimuli reduces the strength of subliminal priming. Cross-correlation analysis will subsequently test whether improved network and perceptual performance after subliminal exposure is consistent with a Hebbian mechanism underlying the increase in functional connectivity specifically for the neurons activated by subthreshold stimuli. Aim 3 will examine the impact of attention on the relationship between subliminal priming and neuronal and perceptual performance. We will test the novel hypothesis that spatial attention reduces the efficacy of subliminal priming – exposure to unattended subliminal stimulation will be associated with a larger improvement in network coding and perceptual performance compared to exposure to attended information. In contrast, we expect that attention will increase the strength of supraliminal priming, i.e., exposure to attended subliminal stimulation will be associated with a larger improvement in network coding and perceptual performance compared to exposure to unattended information. Taken together, our proposed experiments can potentially advance our understanding of information coding in visual cortex by testing the limits of sensory experience and its relationship with perception, which will help develop effective therapies to treat the brain-based aspects of low vision conditions, such as amblyopia, age-related macular degeneration, diabetic retinopathy, or stroke.