NEURAL BASIS OF SHAPE REPRESENTATION AND RECOGNITION

形状表示和识别的神经基础

• 批准号: 8172747
• 负责人: Anitha Pasupathy
• 金额: $ 15.51万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8172747
• 关键词: Animal Behavior; Animals; Brain; Cells; Color; Color Perception; Computer Retrieval of Information on Scientific Projects Database; Funding; Goals; Grant; Image; Institution; Laboratories; Monkeys; Neurons; Pattern; Primates; Research; Research Personnel; Resources; Retinal; Shapes; Source; Stimulus; Training; United States National Institutes of Health; V4 neuron; Visual Cortex; Visual system structure; area V4; base; insight; object recognition; relating to nervous system; research study; response; visual stimulus

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of research in my laboratory is to understand how visual stimuli are encoded in the neural activity patterns in the visual cortex and how this representation underlies object recognition. In one set of experiments we are investigating how partially occluded objects are encoded. In everyday situations objects are often partially occluded but our visual system recognizes objects robustly and efficiently despite retinal image distortions due to partial occlusion. To discover how this is achieved in the primate brain, we have conducted experiments in two fixating monkeys to study activity in area V4 and compare representations when an object is isolated versus when adjoined by a contextual stimulus that suggests partial occlusion. Our results indicate that responses of V4 neurons more closely resemble the perceived stimulus, i.e. V4 neurons do not encode contours that are likely to arise in the retinal image as a result of partial occlusion. In a second experiment, we have trained an animal to perform a shape matching task in the presence of occluders. We will start recording from this animal in a few weeks to study activity of V4 neurons as the animal performs the task. Correlation between neural activity and animal behavior on a single trial basis will provide important insights into how V4 activity is utilized for recognizing objects. Finally, we have found a new class of cells in V4 that respond preferentially to colored stimuli at isoluminance. When the contrast between the stimulus and background increases the neuron is suppressed. We are currently investigating how this neuron contributes to color perception.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我实验室的研究目标是了解视觉刺激是如何在视觉皮层的神经活动模式中编码的，以及这种表征如何成为物体识别的基础。在一组实验中，我们正在研究部分被遮挡的物体是如何编码的。在日常生活中，物体往往被部分遮挡，但我们的视觉系统识别物体鲁棒性和有效性，尽管视网膜图像失真，由于部分遮挡。为了发现这是如何在灵长类动物的大脑中实现的，我们在两只固定的猴子身上进行了实验，研究V4区的活动，并比较了当一个物体被孤立时与当一个物体被一个暗示部分遮挡的上下文刺激毗邻时的表征。我们的研究结果表明，V4神经元的反应更接近所感知的刺激，即V4神经元不编码轮廓，这是可能出现在视网膜图像中的结果，部分闭塞。在第二个实验中，我们训练了一只动物在有遮挡物的情况下执行形状匹配任务。我们将在几周内开始记录这只动物，以研究动物执行任务时V4神经元的活动。在单次试验的基础上，神经活动和动物行为之间的相关性将为V4活动如何用于识别物体提供重要的见解。最后，我们在V4中发现了一类新的细胞，它们优先对等亮度的彩色刺激做出反应。当刺激和背景之间的对比度增加时，神经元就会受到抑制。我们目前正在研究这种神经元如何有助于颜色感知。