Local Circuits & Direction Selectivity in Visual Cortex

描述(摘自申请者摘要)：本项目建议使用 光学成像和单单元记录技术在分析中的应用 雪貂初级视皮层方向特异性的底物。 提出的问题是，单个移动对象存在的各个方面 关于其运动方向的相互冲突的提示(例如，如图所示 光圈中轮廓的运动，或理发杆错觉)。但视觉 系统解决了这些差异，以预测运动的总体方向和 准确的眼球运动指南。拟议的研究详细研究了 V1区神经元群体对运动的反应(通过光学成像) 定向轮廓运动和相同轮廓的终止(其可以是 等同于点运动)。这些实验验证了这样一种假设，即 感知的运动方向是对运动的响应的加权和 刺激中出现了不同的运动方向。这笔金额可以是 受轮廓长度、对比度和速度的影响。单机录制将 用于测试脑内不同时间点单个神经元的特性 光学地图，以验证地图预测，测试可变性 单点响应，以测试终端之间的空间交互作用 和轮廓驱动活动，与电压敏感染料成像一起， 为了检查来自终结器的信号的时间演变的差异和 等高线。

DESCRIPTION (From the Applicant's Abstract): This project proposes using the techniques of optical imaging and single unit recording to analyse the substrates for direction specificity in primary visual cortex of the ferret. The issue raised is that the various aspects of single moving objects present conflicting cues as to the direction of its motion (e.g. as illustrated by motion of contours in an aperture, or the barber pole illusion).Yet the visual system resolves these differences to predict an overall direction of motion and an accurate guide to eye movements. The proposed studies examine in detail the neuron population responses in V1 (by optical imaging) to movement of both oriented contour motion and the terminations of the same contour (which may be equated with dot motion). The experiments test the hypothesis that the perceived direction of motion is a weighted sum of the responses to the different directions of motion present in the stimulus. This sum can be affected by length of contour, contrast and speed. Single unit recording will be used to test the properties of single neurons at different points in the optical maps, to verify the map predictions, to test for variability of responses at single points, to test spatial interactions between terminal point and contour driven activity, and, together with voltage sensitive dye imaging, to examine differences in temporal evolution of signals from terminators and contours.