Causal testing of the role of a place code for global-scale visual features in primate V1 using patterned optogenetics

人类对物体的整体形状高度敏感--这是物体识别的关键步骤。一个假设 大脑使用的是刺激诱发的活动在视觉皮质表面传播的形状 为了处理形状，利用视网膜复制--有充分证据的神经元组织作为 穿过大脑皮层表面的视野。我们小组之前的工作发现，活动的形状 大脑皮层保存的信息可以用来解码刺激的整体形状，但大脑 到目前为止，实际使用这些信息还不清楚。目前的提案旨在检验这样一个假设，即 大脑皮质活动的形状可以通过观察对形状的感知是否可以在视觉上编码形状 是通过人工唤起视觉皮质中的形状活动而产生的。 我将使用光遗传学唤起这种形状的神经元活动，这是一种人工刺激神经元的技术 灯。通过控制激发光的模式，我可以控制我所唤起的活动的形状。如果我能用这个 光遗传刺激对偏向猕猴进行形状辨别任务的报告 与人工插入的活动相对应的形状，这表明大脑依赖于视网膜视功能 大脑皮质中活动的形状，以处理视觉中的形状。 目标1中的实验将描述猕猴执行简化的形状辨别任务的行为 以及在执行任务时记录的神经元信号，并对电位进行详细的计算建模 神经元策略。目标2将侧重于开发精密成型所需的管道 光基因引发的活动。目标3将是一个实验，其中将使用光遗传学来介绍 人工活动将特定形状送入猕猴的视皮层，执行形状辨别任务。 我将看看行为，以及可能的感知，是否会受到人工神经元添加的系统性影响 只有通过其在大脑皮层中传播的形状才能包含信息的活动。拟议中的工作 将对我们理解形状是如何在视觉中处理的做出了重要贡献，并将具有广泛的 图案化的光遗传刺激在翻译语境中的作用，例如用于大脑皮层 恢复视力的神经假体。

Humans are highly sensitive to the overall shape of objects—a critical step in object identification. One hypothesis is that the brain uses the shape of the spread of stimulus-evoked activity across the surface of visual cortex in order to process shape, exploiting retinotopy—the well-documented organization of neurons as a projection of the visual field across the surface of the cortex. Prior work from our group has found that the shape of activity across the cortex holds information that can be used to decode the overall shape of a stimulus, but whether the brain actually uses this information is as of yet unknown. The current proposal aims to test the hypothesis that the shape of activity across the cortex can encode shape in vision by seeing if the perception of shape can be brought about by artificially evoking shaped activity in visual cortex. I will evoke this shaped neuronal activity using optogenetics, a technique for artificially exciting neurons using light. By controlling the pattern of excitation light, I can control the shape of the activity I evoke. If I can use this optogenetic stimulation to bias macaque monkeys performing a shape discrimination task to report seeing the shapes corresponding to the artificially inserted activity, it would indicate that the brain relies on the retinotopic shape of activity across the cortex to process shape in vision. Experiments in Aim 1 will describe the behavior of macaques performing a simplified shape discrimination task and the neuronal signals recorded as they perform the task, with detailed computational modeling of potential neuronal strategies. Aim 2 will be focused on the development of the pipeline necessary for precise shaping of optogenetically evoked activity. Aim 3 will be an experiment in which optogenetics will be used to introduce artificial activity of a specific shape into the visual cortex of macaques performing the shape discrimination task. I will see if behavior, and thus likely perception, is systematically affected by the addition of artificial neuronal activity that only contains information by virtue of the shape of its spread across the cortex. The proposed work will be an important contribution to our understanding of how shape is processed in vision and will have broad implications for the utility of patterned optogenetic stimulation in translational contexts such as for use in cortical neuroprostheses for restoring vision.