CORTICAL SUBSTRATES OF VISUAL MOTION PERCEPTION

视觉运动感知的皮质基底

• 批准号: 2882927
• 负责人: TATIANA PASTERNAK
• 金额: $ 26.77万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2882927
• 关键词: Macaca; behavior test; behavioral /social science research tag; electrostimulus; experimental brain lesion; magnetic resonance imaging; microelectrodes; motion perception; neural information processing; psychophysics; short term memory; visual cortex; visual fields; visual perception; visual stimulus

The visual environment of an active observer is constantly changing, even though its individual features may remain constant. To preserve continuity of visual stimulation, the observer has to not only encode visual information, but also preserve it over brief periods of time. This research is aimed at examining properties of this temporary storage mechanism. We will also explore the role of selected extrastriate cortical areas in storing one of the fundamental features of the visual stimulus, its direction of motion. We chose this feature because its neural coding is well understood and some cortical areas involved in its processing have been identified. These studies will provide important new information concerning the possible participation of visual cortical areas in circuitry subserving visual short-term memory. Proposed experiments will use psychophysical measures, microstimulation and lesions of physiologically identified regions in selected extrastriate cortical areas to investigate the temporary storage (i.e. short-term memory) of directional information. I. Psychophysical properties of mechanisms mediating short-term memory for stimulus motion - The first group of experiments will explore the nature of the process underlying the storage of motion information, in particular its spatio-temporal and directional tuning, retinotopy, and the efficacy of different types of stimulus noise in degrading storage. The monkeys will be tested in a visual task in which two visual stimuli, the sample and the test, separated in time will be judged as the same or different. These studies will provide a better understanding of the mechanisms mediating the retention of motion information, help determine the level of cortical processing at which visual information is stored and set the stage for subsequent studies of neural substrates underlying visual memory. II. The role of areas MT, V3 and V4 in discrimination and storage of stimulus direction and orientation - The goal of this portion of the project is to determine the role of visual areas identified with motion analysis, areas V3 and MT, in the processing and storage of information about stimulus direction. We will use intracortical microstimulation of physiologically identified sites and the lesion approach. To determine the specificity of the effects produced by these manipulations, we will also use non-motion tasks requiring discrimination and retention of stimulus orientation, and apply the same manipulations to localized portions of area V4, which has been identified with form processing. This will help clarify how hierarchical and parallel cortical streams mediate both perception and recall of stimulus features.

一个活跃的观察者的视觉环境是不断变化的，即使 尽管其各个特征可以保持不变。保存 视觉刺激的连续性，观察者不仅要编码 视觉信息，但也可以在短时间内保存它。这 研究的目的是检查这种临时存储的特性 机制我们还将探索选定的外纹的作用 大脑皮层区域储存视觉的基本特征之一， 刺激，运动方向。我们选择这个功能是因为它 神经编码是很好的理解和一些皮质区参与其 加工已经确定。这些研究将提供重要的新 关于视觉皮层可能参与的信息 视觉短期记忆的回路区域。 拟议的实验将使用心理物理措施，微刺激 和病变的生理上确定的区域，在选定的 纹状体外皮质区，以研究临时存储（即， 短期记忆）的方向信息。 I.短时记忆调节机制的心理物理学特性 刺激运动-第一组实验将探讨 运动信息存储的基本过程的性质， 特别是它的时空和方向调谐，视网膜， 不同类型的刺激噪声在降低存储中的功效。 猴子将在视觉任务中进行测试，其中两个视觉刺激， 样本和测试，在时间上分开，将被判断为相同或 不同.这些研究将使人们更好地了解 调节运动信息保留的机制，有助于确定 储存视觉信息的皮层处理水平 并为随后的神经基质研究奠定了基础 视觉记忆 二. MT、V_3和V_4区在识别和储存脑电中的作用 刺激方向和方向-这部分的目标 项目是确定视觉领域的作用，确定与运动 信息处理和储存方面的V3和MT分析 关于刺激的方向。我们将使用皮质内微刺激 生理学上确定的部位和病变入路。以确定 这些操作产生的效果的特异性，我们将 也使用非运动任务，需要区分和保留 刺激方向，并对局部应用相同的操作 区域V4的一部分，其已经用表单处理识别。这 将有助于阐明层次和平行的皮层流如何介导 刺激特征的感知和回忆。