Linking neural population activity and visual perception

描述（由申请人提供）：拟议研究的总体目标是提供对灵长类视觉皮层（V1）神经活动与模式检测任务中行为表现之间关系的定量理解。为了实现这一目标，将训练猴子执行要求苛刻的视觉检测任务。当猴子执行这项任务时，我们将使用电压敏感染料结合电生理学的光学成像来监测V1中的神经群体活动。详细了解V1的神经反应和行为表现之间的关系，在这个任务中需要解释三组变量之间的关系：视觉刺激，V1的神经反应，和受试者的心理物理性能的检测任务。我们的前两个目标集中在这三个变量之间的两个基本因果关系。在目标#1中，我们的目标是确定关于目标和背景的视觉信息如何由V1神经元群体表示。我们将解决三个主要问题：（i）V1提供给视觉系统其他部分的信号的质量如何，（ii）这些信息在V1中是如何分布的，以及（iii）从V1中提取这些信息的最佳方式是什么？为了形成关于目标存在或不存在的决定，V1之后的神经回路必须“读出”并解释由V1神经元群体提供的神经信号。我们在目标#2中的目标是确定V1中的哪些神经元有助于关于目标存在的感知决策，以及如何将它们的信号合并以形成此决策。最后，这两个基本关系--V1神经元对视觉信息的编码，以及后续处理阶段对V1反应的解码--可能会发生变化，这取决于行为任务。在目标3中，我们建议通过改变目标的不确定性来改变任务。我们将研究目标不确定性对V1中的行为反应和神经反应的影响。

DESCRIPTION (provided by applicant): The overall goal of the proposed research is to provide quantitative understanding of the relationship between neural activity in the primate visual cortex (V1) and behavioral performance in pattern detection tasks. To achieve this goal, monkeys will be trained to perform a demanding visual detection task. While the monkey performs this task, we will use optical imaging with voltage sensitive dyes in conjunction with electrophysiology, to monitor neural population activity in V1. Detailed understanding of the relationship between neural responses in V1 and behavioral performance in this task necessitates explanations of the relationships between three sets of variables: the visual stimuli, neural responses in V1, and the subject's psychophysical performance on the detection task. Our first two aims focus on two fundamental causal relationships between these three variables. In Aim #1 our goal is to determine how visual information regarding the target and the background is represented by populations of V1 neurons. We will address three primary questions: (i) what is the quality of the signals that are provided by V1 to the rest of the visual system, (ii) how is this information distributed in V1, and (iii) what is the optimal way to extract this information from V1? To form a decision regarding the presence or absence of the target, neural circuits subsequent to V1 must 'read out' and interpret the neural signals provided by populations of V1 neurons. Our goal in Aim #2 is to determine which neurons in V1 contribute to the perceptual decision regarding the presence of the target, and how their signals might be pooled to form this decision. Finally, these two fundamental relationships - the encoding of visual information by V1 neurons, and the decoding of V1 responses by subsequent processing stages - may change, depending on the behavioral task. In Aim #3, we propose to vary the task by changing target uncertainty. We will examine the effects of target uncertainty on both behavioral responses and neural responses in V1.