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: 8392962
• 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/8392962
• 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; public health relevance; 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.

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对视觉上相似对象的快速准确识别。这对于识别单个面孔的识别尤其重要，而细微的差异在行为上至关重要。一方面，面部识别是高度精确的，因为它需要歧视非常相似的视觉刺激。另一方面，它是灵活的，因为尽管其视网膜图像有很大的变化，但我们可以轻松而快速地识别出特定的面孔。不知何故，面部识别（以及对其他特定物体的识别）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多数详细知识都来自血氧水平依赖性（粗体）功能磁共振成像（fMRI）。尤其是，fMRI已经确定了颞皮层腹侧部分的特定区域，即梭形面部（FFA），对面部的反应比对任何其他类别的视觉对象的反应要强得多。尽管它的名称，FFA在识别面部的确切作用尚不清楚，部分原因是FFA中神经活动与大胆的FMRI信号之间的间接关系。为了允许直接测量FFA中的神经活动，我们的实验将使用患者植入的电极进行癫痫评估。这些植入物提供了一个独特而安全的机会，可以以否则不可能的方式直接从人皮层记录电生理学。尽管FFA对面对面的大胆响应通常大于对其他物体的响应，但FFA对不同单个面的响应可能相似，这可能是因为大胆响应平均许多神经元在时空上的反应。但是，使用FFA中的活动直接记录，我们将确定在单个试验中从FFA记录的刺激引起的局部田间电位是否可以区分两个不同的面部。 PI还将使用这些记录来确定FFA中的神经活动是否构成我们识别面部大小和位置差异的能力。最后，我们将测试FFA是否对面对身份的判断至关重要。神经元种群对行为的重要性的关键测试是其活动与行为表现之间的联系。我们将检查在各个试验中的FFA活动与行为之间的相关性，因为受试者认识到变形的面孔。这些相关性将提供有力的证据，表明FFA参与了歧视单个面孔的歧视。提出的实验检查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？）也与临床相关。视觉感知的障碍是由于创伤和中风而受到的脑损伤受害者的经常且严重的认知缺陷，这反过来又是当今美国退伍军人面临的主要问题。更好地了解人脑中的视觉对象的处理可能会为这些残疾障碍的病理生理学和康复提供重要的见解。