Perceptual Modulation of Microcircuit Dynamics Across Cortical Face Patches

描述（由申请人提供）： 我们的视觉系统是在自然环境中进化而来的，我们有理由认为，我们的视觉系统被塑造得更善于识别一组与生态相关的物体。人脸感知是一项重要的功能，它向我们传达了有关身份，性别和情绪的信息，这些信息在社会和情感互动中非常有用。最近有人提出，人类和猕猴共享大部分的皮质面部处理机制。在这种情况下，这个项目的一般目的是剖析参与检测的面部刺激的多个功能的神经机制，并测试系统是否在有意识和无意识的人脸可见性中发挥作用。支持这一总体目的的概念和方法框架是基于一个新的实验平台，包括耦合功能磁共振成像功能映射面部选择性皮层补丁和多电极/刺激技术，以记录特定的细胞特性在每个补丁和测试猕猴的因果关系。第一个目标将追求的特点，调整专业化和方向性的信息流在面对补丁。选择性的出现将通过分析偏好和反偏好的面部空间来检查，以研究局部皮质抑制是否起作用。一旦完成了第一步，将使用干扰技术来测量对人工刺激和自然视觉刺激的神经反应。第二组实验将评估检测任务中神经信号（单个单元和LFP）与行为反应之间的相关性和因果关系。一旦系统模型被初步表征，该项目的最后部分将确定有意识和无意识人脸识别的神经特征。感知可见性操纵将使用对象替代掩蔽来实现，对象替代掩蔽是人类中广泛使用的心理物理范例，其允许对感知刺激进行系统控制。我假设，视觉信息可以达到早期节点的补丁系统的前馈方式，建立选择性，即使在近阈值的视觉刺激介绍，这种模式可以从知觉意识，这需要反馈机制分离。这些相互关联的方法使用的人脸补丁系统作为一个专门的模型，用于视觉对象识别，提高了揭示新的信息的内部运作调解视觉对象感知的可能性。 公共卫生相关性： 我们每天都能毫不费力地在许多情况下认出我们的同类，这种能力使我们能够推断出最终指导我们即时行为的情绪状态。我们能够做到这一点，强调了理解面部处理的内部工作机制的重要性。该项目的重点是获得有关神经机制的知识，这些神经机制介导面部可见性并最终将物体识别作为一个整体。该研究提案的区别在于，它采用了一种方法论方法的组合，旨在解开生物实现的人脸识别作为一个生态相关的对象类别在最近定义良好的大脑网络。

DESCRIPTION (provided by applicant): Our visual system evolved in a natural environment, and is reasonable to assume that it has been sculpted to be better at recognizing a definite ecological relevant set of objects. Face perception is an essential feat that conveys to us information about identity, gender, and mood which is useful in social and emotional interactions. It has been recently suggested that humans and macaques share most of the cortical face processing machinery. In this vein, the general purpose of this project is to dissect the neural mechanisms participating in detection of multiple features of face stimuli, and test if the system plays a role during conscious and unconscious visibility of faces. The conceptual and methodological framework supporting this general purpose is grounded on a novel experimental platform consisting in coupling fMRI to functionally map face-selective cortical patches and multielectrode/stimulation techniques to record specific cell properties within each patch and test for causal relationships in macaque monkeys. The first aim will pursue to characterize tuning specialization and directionality of information flow across face patches. Emergence of selectivity will be examined analyzing preferred and anti-preferred face spaces to investigate if local cortical inhibition plays a role. Once this first step is achieved, interference techniques to measure neural responses to artificial stimulation and to natural visual stimulation will be used. The second set of experiments will evaluate the correlation and causal link between neural signals (single unit and LFP) and behavioral responses in a detection task. Once the system model has been initially characterized, the final part of this project will determine the neural signature of conscious and unconscious face recognition. Perceptual visibility manipulations will be achieved using an object-substitution masking, a widely used psychopysical paradigm in humans that permit a systematic control of the perceived stimulus. I hypothesize that visual information can reach early nodes of the patch system in a feedforward fashion, building up selectivity even at near-threshold visual stimuli presentations, and that this mode can be dissociated from perceptual awareness, which requires feedback mechanisms. These interrelated approaches using the face patch system as a specialized model for visual object recognition enhances the probability of revealing novel information of the inner workings mediating visual object perception. PUBLIC HEALTH RELEVANCE: We daily recognize our conspecifics without any effort and in many contexts and this ability allows us to infer emotional states that ultimately guide our immediate behavior. Our ability to perform this stresses the importance of understanding the inner workings of face processing. This project is centered on gaining knowledge on the neural mechanisms that mediate face visibility and eventually object recognition as a whole. The research proposal is distinguished because it employs a combination of methodological approaches intended to disentangle the biological implementations of face recognition as an ecological relevant object category in a recently well defined brain network.