NEURAL MECHANISMS FOR NATURAL VISION

我们的长期目标是了解复杂形式视觉的神经基础，因为它在自然观看条件下运作。几十年的视觉研究使用简单的刺激和受控的观看条件，已经产生了早期视觉系统处理的复杂模型。我们建议通过记录模拟自然视觉条件下的反应来直接评估这些模型。在目标1中，我们建议使用自然和更标准的传统刺激来获取V1区域的数据。定量方法将用于从这些数据中估计细胞的时空过滤特性。实验和分析将揭示V1如何在自然视觉中表示和处理信息。他们还将揭示这些功能与使用传统简单刺激的实验预测的功能有何不同。在目标2中，我们将评估V1区域的一系列功能计算模型，以确定那些可以解释在模拟自然视觉期间观察到的响应的模型。这将通过模型之间的直接统计比较来完成。这一目标的成功完成将产生第一个计算模型，可以解释V1神经元在自然视觉过程中的时空反应。在目标3中，我们将评估视网膜外因素的调节影响，如在模拟自然视觉过程中的注意力。我们建议通过将标准的匹配样本行为任务与我们的自然刺激和定量接受野估计方法相结合来做到这一点。这将为V1区潜在的视网膜外效应提供一个敏感的测量方法。关于自然视觉的实验很重要，因为它们将使我们能够评估我们目前关于人类视觉皮层功能的理论，并确定我们理解薄弱的领域。它们还将使我们能够解决形式视觉的复杂方面，这些方面无法使用更传统的方法轻松接近。

Our long term goal is to understand the neural basis of complex form vision as it operates under natural viewing conditions. Decades of vision research using simple stimuli and controlled viewing conditions have produced sophisticated models of processing in the early visual system. We propose to evaluate these models directly by recording responses under conditions simulating natural vision. In Aim 1 we propose to acquire data in area V1 using both naturalistic and more standard conventional stimuli. Quantitative methods will be used to estimate cells' spatio-temporal filtering properties from these data. The experiments and analyses will reveal how are V1 represents and processes information during natural vision. They will also reveal how these functions differ from those predicted from experiments using conventional simple stimuli. In Aim 2, we will evaluate a range of functional computational models of area V1 to identify those models that can account for responses observed during simulated natural vision. This will be accomplished by direct statistical comparison between models. Successful completion of this Aim will result in the first computational model(s) that can account for the spatio-temporal responses of V1 neurons during natural vision. In Aim 3 we will assess the modulatory influence of extra-retinal factors such as attention during simulated natural vision. We propose to do this by combining standard match-to-sample behavioral tasks with our naturalistic stimuli and our quantitative receptive field estimation methods. This will provide a sensitive measure of potential extra-retinal effects in area V1. Experiments on natural vision are important because they will allow us to evaluate our current theories of human visual cortical function and identify areas in which our understanding is weak. They will also allow us to address complex aspects of form vision that cannot easily be approached using more conventional methods.