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Neurophysiology of Visual Perception

视觉感知的神经生理学

基本信息

批准号：
9568260
负责人：
David A Leopold
金额：
$ 46.01万
依托单位：
NATIONAL INSTITUTE OF MENTAL HEALTH
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9568260
关键词：
Ablation Adult Affect Area Attention Behavior Blinking Brain Callithrix Cell Nucleus Complex Cues Darkness Data Analyses Development Dimensions Distant Electrodes Electrophysiology (science)Elements Environment Esthesia Event Evolution Eye Eye Movements Faculty Functional Magnetic Resonance Imaging Human Image Individual Laboratories Life Light Macaca Mammals Manuals Maps Measures Mental disorders Methods Modeling Molds Motion Nervous system structure Neurons Paper Parietal Lobe Pathway interactions Patients Pattern Perception Persons Positioning Attribute Preparation Primates Process Publishing Pulvinar structure Research Resolution Retina Retinal Role Semantics Series Shapes Signal Transduction Stimulus Structure Surface Thalamic Nuclei Thalamic structure Time Vision Vision Disparity Visual Visual Cortex Visual Pathways Visual Perception Work area V1 area striata experience experimental study extrastriate visual cortex impression interest movie nervous system disorder neurophysiology nonhuman primate novel postnatal programs receptive field relating to nervous system remote sensing response two-dimensional visual information

项目摘要

To understand our vision, it is critical to place humans within an appropriate phylogentic context: humans are primates, and their dominant use of vision is typical of primates and different from other mammals. As a sensing faculty, vision places individuals at a great advantage over their environment, allowing them to remotely sense complex details from a safe distance. As this context is critical for our research, we recently published a comprehensive review describing the distinguishing features of primate vision against a mammalian background, and thus placing human vision into its proper evolutionary context (Leopold, Freiwald, and Mitchell, Evolution of Nervous Systems, ed. Kaas, 2017). Much of our research on visual perception centers on how we see shapes, objects, and scenes. From the moment light enters the eyes, our percept is molded by a series of processing stages, crafted through years of visual experience during primates unusually long period of development. In our laboratory, we combine fMRI and electrophysiology to ask questions such as, how does the brain create a three-dimensional representation of the world, given that its retinal images are inherently two-dimensional? How do we complete surfaces, distinguish between foreground and background, and understand the difference between real motion and the motion caused by our own eye movements? These types of questions are present in each of our research lines. Here we described several studies that focus on particular sub-questions. In the past two years, we have placed most of our emphasis studying visual perception on the mysterious role of the large pulvinar nucleus of the thalamus, which projects to multiple visual areas including the primary visual cortex (V1). In one set of studies, we have been investigating electrical activity across the pulvinar using a novel electrode mapping approach. This large project has yielded two papers currently in preparation (Murphy et al. and (Deng et al.. We have recently published a comprehensive review paper on the pulvinar, (Bridge et al., 2016), which focuses on multiple aspects of its structure and function, including a newly hypothesized transient visual pathway that precedes that adult geniculostriate pathway that conveys early postnatal visual information. We have recently submitted a large collaborative study investigating the role of early-life ablation of one small pulvinar nucleus, and the effect of its disruption on visually-guided manual behavior in the adult (Mundinano et al., 2017), under review. We have also made progress on activity in the visual cortex, focusing on several features of area V1. In one study, currently under review (Cox et al., 2017)), we have studied the effects of a brief attentional cue on activity outside neurons receptive fields within V1, with the results suggesting that there is effectively an activity blink just following the presentation of meaningful cues. We further investigated the entrainment of spiking and gamma-range LFP activity by alpha signals (Dougherty et al., 2017). We also published a paper showing that the ablation of are V1 does not disrupt but rather enhances activity correlation in higher-order visual areas (Shapcott et al., 2016). Finally, in a collaborative study, we found that human patients with damage to the parietal cortex were selectively affected in their perception of binocular disparity (Murphy et al., 2016). In our work on visual perception, we have been increasingly interested in the brains responses to stimuli that are not simply flashed on the screen but that rather evolve over time. To this end, we have conducted multiple studies in which macaques and marmosets freely view dynamic video stimuli. From an experimental perspective, data analysis from this type of experiment can be challenging, as there is inherent variability in the subjects eye positions. In one study, we systematically examined the regional fMRI responses to the subjects eye movements, and compared them to the fMRI responses to the events in the movie itself (Russ et al., 2016). We found that the activity patterns under these two conditions were very different. In a very recent study, we used both fMRI and electrophysiology to create a new means to classify neural responses using fMRI maps (Park et al., 2017). This method demonstrated that neurons within hundreds of microns of one another were affiliated in very different ways with distant brain areas. These and other results from the natural viewing paradigm have raised a number of new questions about how the brain interprets its retinal images, and we are currently in the process of focusing on the temporal dynamics of the responses, asking to what extent neural responses integrate temporal integration over time (Russ et al., in preparation).

为了理解我们的视觉，将人类置于一个适当的系统发育背景中是至关重要的：人类是灵长类动物，他们对视觉的主要使用是灵长类动物的典型特征，与其他哺乳动物不同。作为一种感知能力，视觉使个体在环境中具有很大的优势，使他们能够从安全的距离远程感知复杂的细节。由于这一背景对我们的研究至关重要，我们最近发表了一篇全面的综述，描述了灵长类动物视觉与哺乳动物背景的区别特征，从而将人类视觉置于适当的进化背景中（Leopold, Freiwald, and Mitchell, Evolution of Nervous Systems, ed. Kaas, 2017）。