Cortical encoding of unconscious visual information and its impact on behavior

项目摘要/摘要 然而，呈现得太短而不被注意到的刺激仍然可以促进对相同刺激的知觉处理 许多分钟后的刺激。尽管潜意识启动现象早在几十年前就已为人所知， 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 通过神经元回路影响随后的感觉处理仍然是一个谜。我们将回答这些问题 通过在单细胞分辨率下检查是否暴露在潜意识刺激中来首次提出问题 影响视觉大脑皮层群体的知觉表现和信息编码。至 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位活动 水平视觉皮质区域(V1和V4)和行为技术，以检查动态和编码 潜意识暴露期间和之后的神经元数量及其对知觉表现的影响。目标1 将调查暴露在潜意识刺激下是否会增加随后的知觉表现，以及 人口活动中编码的信息量。我们的假设是，潜意识暴露会改善 当刺激随后呈现在可检测性之上时的知觉辨别性能 阈值，并增加从人口反应中提取的信息量。Aim 2将检查 潜伏期暴露后改善神经元和行为功能的机制。我们会 第一个重点是涉及光遗传失活的因果实验，它将测试抑制 阈下刺激呈现时视觉皮层神经元活动降低阈下刺激强度 引爆。互相关分析随后将测试改进的网络和感知 潜意识暴露后的表现符合Hebbian机制，其背后的增加 亚阈值刺激激活的神经元的功能连接。目标3将研究 注意对阈下启动与神经元和知觉表现关系的影响。 我们将检验这一新的假设，即空间注意降低了潜意识启动的有效性-暴露于 无人值守的潜意识刺激将与网络编码的更大改进和 将知觉表现与接触所关注的信息进行比较。相比之下，我们希望这种关注 将增加阈值上启动的强度，即暴露在受人注意的阈值下刺激将是 在网络编码和感知性能方面与暴露于 无人参与的信息。综上所述，我们提出的实验可能会促进我们对 通过测试感觉经验的极限及其与视觉的关系，对视觉皮层的信息编码进行研究 感知，这将有助于开发有效的治疗方法，以治疗基于大脑的低视力状况， 如弱视、老年性黄斑变性、糖尿病视网膜病变或中风。

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.