Mechanism of Rapid Object Recognition in Human Ventral Temporal Cortex

人类腹侧颞叶皮层快速物体识别机制

• 批准号: 8044320
• 负责人: DANIEL YOSHOR
• 金额: --
• 依托单位: MICHAEL E DEBAKEY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8044320
• 关键词: Affect; Area; Behavior; Behavioral; Brain; Brain Injuries; Categories; Cognitive deficits; Craniocerebral Trauma; Data; Discrimination; Electrodes; Epilepsy; Face; Functional Magnetic Resonance Imaging; Functional disorder; Human; Human Activities; Image; Impairment; Implant; Implanted Electrodes; Individual; Judgment; Knowledge; Measurement; Mental Processes; Names; Neurons; Neurosciences; Patients; Pattern; Performance; Population; Positioning Attribute; Probability; Process; Property; Rehabilitation therapy; Reporting; Resolution; Retinal; Role; Signal Transduction; Stimulus; Stroke; Surface; Techniques; Temporal Lobe; Testing; Time; Trauma; Variant; Veterans; Visual; Visual Agnosias; Visual Perception; Visual system structure; Word Processing; base; behavioral tolerance; blood oxygen level dependent; clinically relevant; extrastriate visual cortex; face perception; flexibility; fusiform face area; implantation; injured; insight; millisecond; neurophysiology; object recognition; relating to nervous system; research clinical testing; research study; response; visual information; visual object processing; visual stimulus

DESCRIPTION (provided by applicant): One of the most challenging tasks performed by our visual system is the rapid and accurate identification of visually similar objects. This is particularly important for recognition of individual faces, where subtle differences are behaviorally crucial. On one hand, face recognition is highly precise, as it entails discrimination of very similar visual stimuli. On the other hand, it is flexible, as we can effortlessly and rapidly recognize a specific face in spite of considerable variations in its retinal image. Somehow, the cortical mechanisms that underlie face recognition (as well as recognition of other specific objects) are simultaneously both strict and tolerant. Most of our detailed knowledge about how the human brain recognizes faces and other objects comes from blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI). In particular, fMRI has identified a specific area in the ventral part of the temporal cortex, the fusiform face area (FFA) that responds much more strongly to faces than to any other category of visual object. Despite its name, the precise role of the FFA in recognizing faces is unclear, partly because of the indirect relationship between neural activity in the FFA and the BOLD fMRI signal. To allow for direct measurement of neural activity in the FFA, our experiments will be conducted using electrodes implanted in patients for the clinical evaluation of epilepsy. These implantations offer a unique and safe opportunity to directly record electrophysiological from human cortex in a way that is otherwise not possible. Although the BOLD response in the FFA to faces in general is greater than the response to other objects, the response in FFA to different individual faces is similar, likely because the BOLD response averages the response of many neurons over space and time. However, using direct recording of activity in the FFA, we will determine if stimulus-evoked local field potentials recorded from FFA in single trials can discriminate between two different faces. The PI will also use these recordings to determine if neural activity in the FFA underlies our ability to recognize a face in spite of variations in its size and position. Finally, we will test whether that the FFA is critical to judgments about face identity. A key test of the importance of a neuronal population for behavior is the connection between its activity and behavioral performance on a trial-by-trial basis. We will examine correlations between FFA activity and behavior across individual trials as a subject recognizes morphed faces. These correlations would provide powerful evidence that FFA is involved in discrimination of individual faces. The proposed experiments examine a fundamental question in neuroscience (what is the neural basis of human visual perception?) that is also clinically relevant. Impairments in visual perception are a frequent and significant cognitive deficit in victims of acquired brain injuries due to trauma and stroke, which in turn are major problems facing U.S. veterans today. A better understanding of how visual objects are processed in the human brain may provide important insights into the pathophysiology and rehabilitation of these disabling impairments. PUBLIC HEALTH RELEVANCE: Many of the U.S. veterans with acquired brain injuries due to head trauma or stroke suffer a loss in their ability to cognitively process the word around them. Little is know about the brain allows us to process our surroundings, and there is currently very little that can be done to rehabilitate or treat patients with disabling deficits in mental processing. Our project uses a unique opportunity to directly observe the human brain's activity in order to study how the brain enables us to recognize specific objects. A better understanding how the brain is miraculously able to process visual information should ultimately help us better treat patients with injured brains.

描述（由申请人提供）： 我们的视觉系统执行的最具挑战性的任务之一是快速准确地识别视觉上相似的物体。这对于识别个体面孔尤其重要，其中细微的差异在行为上至关重要。一方面，人脸识别非常精确，因为它需要区分非常相似的视觉刺激。另一方面，它是灵活的，因为我们可以毫不费力地快速识别特定的面孔，尽管其视网膜图像存在相当大的变化。不知何故，面部识别（以及其他特定物体的识别）背后的皮质机制同时既严格又宽容。我们关于人脑如何识别面部和其他物体的大部分详细知识都来自于血氧水平依赖性（BOLD）功能磁共振成像（fMRI）。特别是，功能磁共振成像已经识别出颞叶皮层腹侧部分的一个特定区域，即梭形面部区域（FFA），它对面部的反应比对任何其他类别的视觉物体的反应都要强烈得多。尽管有其名称，但 FFA 在识别面部中的确切作用尚不清楚，部分原因是 FFA 中的神经活动与 BOLD fMRI 信号之间存在间接关系。为了能够直接测量 FFA 中的神经活动，我们的实验将使用植入患者体内的电极进行癫痫的临床评估。这些植入提供了一个独特且安全的机会，以一种其他方式无法实现的方式直接记录人类皮层的电生理信息。虽然 FFA 对面部的 BOLD 反应通常大于对其他物体的反应，但 FFA 对不同个体面部的反应是相似的，可能是因为 BOLD 反应平均了许多神经元在空间和时间上的反应。然而，通过直接记录 FFA 中的活动，我们将确定在单次试验中从 FFA 记录的刺激诱发的局部场电位是否可以区分两个不同的面孔。 PI 还将使用这些记录来确定 FFA 中的神经活动是否是我们识别面部的能力的基础，无论其大小和位置如何变化。最后，我们将测试 FFA 对于面部身份判断是否至关重要。神经元群对行为重要性的关键测试是在逐次试验的基础上其活动与行为表现之间的联系。当受试者识别变形面孔时，我们将在各个试验中检查 FFA 活动和行为之间的相关性。这些相关性将为 FFA 参与个人面孔歧视提供有力的证据。拟议的实验研究了神经科学中的一个基本问题（人类视觉感知的神经基础是什么？），这也与临床相关。视觉感知障碍是外伤和中风导致的后天性脑损伤受害者中常见且严重的认知缺陷，这也是当今美国退伍军人面临的主要问题。更好地了解视觉对象在人脑中的处理方式可能会为这些致残障碍的病理生理学和康复提供重要的见解。 公共卫生相关性： 许多因头部外伤或中风而遭受脑损伤的美国退伍军人，认知处理周围事物的能力都受到损失。我们对大脑能够处理周围环境的了解甚少，目前可以采取的措施也很少，可以帮助患有心理处理缺陷的患者康复或治疗。我们的项目利用一个独特的机会直接观察人类大脑的活动，以研究大脑如何使我们能够识别特定的物体。更好地了解大脑如何奇迹般地处理视觉信息最终应该有助于我们更好地治疗大脑受伤的患者。