Object, face, body and scene representations in the human brain

人脑中的物体、面部、身体和场景表征

• 批准号: 10266613
• 负责人: Christopher Baker
• 金额: $ 135.81万
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 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/10266613
• 关键词: Address; American; Anterior; Behavioral; Body part; Brain; Brain imaging; Brain region; Categories; Cognition; Cognitive; Complex; Computer Models; Consensus; Contracts; Databases; Dimensions; English Language; Event; Eye; Face; Face Processing; Follow-Up Studies; Functional Magnetic Resonance Imaging; Goals; Grain; Hand; Human; Image; Knowledge; Learning; Leg; Light; Magnetoencephalography; Measures; Medial; Memory; Mental Health; Names; Nature; Neurosciences; Parietal Lobe; Participant; Perception; Psychology; Research; Resolution; Resources; Retina; Role; Sampling; Series; Social Behavior; Stimulus; Time; Visual; Visual Cortex; Visual Perception; Work; base; behavior measurement; cognitive process; computer science; crowdsourcing; diverse data; experience; experimental study; falls; foot; insight; interest; large-scale database; memory recall; mental representation; nervous system disorder; recruit; tool; visual imagery; visual stimulus; volunteer

The goal of this research is to understand how we see what we see: how does the brain analyze the light falling on the retina of the eye to reveal a world full of objects, people and things? During the past year we have focused on both (i) perception and (ii) memory of complex visual stimuli, in particular real-world visual scenes, objects and people (NCT00001360). Perception: Real-world scenes are incredibly complex and heterogeneous, yet we are able to categorize them and identify objects and people within those scenes effortlessly. While prior studies have identified brain regions that appear to be specialized for processing faces, object and scenes, it remains unclear what the precise roles of these different regions are and what information they contain. One of the major challenges in understanding visual perception in the brain is the wide range of different objects and scenes that we experience. Despite this breadth, studies often focus on a small number of hand selected object or scene categories, but it becomes unclear how representative any subsequent findings are. To overcome this challenge we developed a large-scale database (THINGS) of 1,854 diverse types of object sampled systematically from concrete picturable and nameable nouns in the American English language. This database provides a rich resource of object concepts and object images and offers a tool for both systematic and large-scale naturalistic research in the fields of psychology, neuroscience, and computer science. We used this database in a large-scale behavioral experiment using online crowdsourcing, sampling 1.46 million trials in more than 5,000 participants. Using a computational model of the task, we were able to identify 49 core dimensions of our internal mental representations of objects, providing a comprehensive and fine-grained characterization of this representational space. These results provide important insights into the cognitive processes supporting our understanding of objects. We are now extending this work to reveal the underlying brain mechanisms by collecting fMRI and magnetoencephalography (MEG) data for this diverse set of object images. Memory: To understand the nature of object and scene memory, we have focused on two specific issues: 1) Organization of the medial parietal cortex Human medial parietal cortex (MPC) has been implicated in multiple cognitive processes including memory recall, visual scene processing and navigation. Given such diverse recruitment of MPC across cognitive domains historically considered largely independent, it is not surprising that there has been no clear consensus with regard to its function and overarching organization. In a series of studies, we measured brain activations with fMRI while we presented participants with images of scenes and people and also asked them to recall specific events (e.g. shaving, going to a beach) as well as recall famous or personally familiar places and people. Our findings revealed two key insights. First, we found an apparent gradient of representation from more perceptually related to more memory related from posterior to anterior within MPC. Second, we found distinct subdivisions within MPC that were active differentially during recall of either people or places. While people and places are two of the most important things we recall from memory, we can also recall specific objects, and separate regions have been identified in visual cortex that appear to be specialized for processing faces, scenes and objects. In follow-up studies we have been addressing whether recall of objects also recruits a separate region in MPC, and how the activations elicited by recall of objects and scenes compares with that elicited by perception of the very same stimuli. Collectively, these results provide a new framework for understanding the functional role of MPC and its significance during different aspects of cognition. 2) Elucidating the content of scene memory When we recall a previously experienced event, what exactly are we remembering? Are our memories a precise, high-definition recording of that event, a low-resolution gist of that memory, or even just a verbal description of what we saw? Answering this question is an essential component of being able to tease apart the mechanisms of memory: what information is encoded and maintained, how memory decays over time, and what information is retrieved from these memories. In a series of studies, we have been investigating the content of memory for real world scenes using a drawing task. Participants study scenes and then after a delay, draw those scenes in as much detail as possible from memory. The resulting memory-based drawings are scored by thousands of online observers, revealing numerous objects, few memory intrusions, and precise spatial information. We have studied both young volunteers as well as people who claim to have no visual imagery (termed aphantasia). Further, we have investigated a common distortion that occurs in memory in which the boundary of the scene is either extended or contracted. Our findings show that not only is it possible to quantify the content of memory during free recall, but that those memories contain detailed representations of our visual experiences (although memory distortions may still occur). Elucidating how the brain enables us to recognize objects, scenes, faces and bodies provides important insights into the nature of our internal representations of the world around us. Understanding these representations is vital in trying to determine the underlying deficits in many mental health and neurological disorders.

这项研究的目的是了解我们如何看到我们所看到的：大脑如何分析落在眼睛视网膜上的光线，以揭示一个充满物体，人和事物的世界？ 在过去的一年里，我们专注于（i）感知和（ii）复杂视觉刺激的记忆，特别是现实世界的视觉场景，物体和人（NCT 00001360）。 感知： 现实世界的场景是非常复杂和异构的，但我们能够对它们进行分类，并毫不费力地识别这些场景中的对象和人。虽然先前的研究已经确定了似乎专门用于处理面部，物体和场景的大脑区域，但仍不清楚这些不同区域的确切作用以及它们包含的信息。 理解大脑中视觉感知的主要挑战之一是我们所经历的各种不同的物体和场景。尽管如此广泛，研究往往集中在少数手选择的对象或场景类别，但它变得不清楚如何代表任何后续的研究结果。 为了克服这一挑战，我们开发了一个大型数据库（THINGS），其中包含1,854种不同类型的对象，这些对象从美国英语中具体的可图示和可命名的名词中系统地采样。该数据库提供了丰富的对象概念和对象图像资源，并为心理学，神经科学和计算机科学领域的系统和大规模自然主义研究提供了工具。 我们在一个大规模的行为实验中使用了这个数据库，这个实验使用了在线众包，在5,000多名参与者中抽样了146万次试验。使用该任务的计算模型，我们能够识别出我们对物体的内部心理表征的49个核心维度，为这个表征空间提供了全面且细粒度的表征。 这些结果提供了重要的见解支持我们的理解对象的认知过程。我们现在正在扩展这项工作，通过收集功能磁共振成像和脑磁图（MEG）数据来揭示这些不同的物体图像的潜在大脑机制。 内存： 为了理解对象和场景记忆的本质，我们关注了两个具体问题： 1)内侧顶叶皮质的组织 人类内侧顶叶皮层（MPC）参与了多种认知过程，包括记忆回忆、视觉场景处理和导航。鉴于MPC在历史上被认为是独立的认知领域中的多样性招聘，关于其功能和总体组织没有明确的共识也就不足为奇了。在一系列的研究中，我们用功能磁共振成像测量了大脑的激活，同时我们向参与者展示了场景和人物的图像，并要求他们回忆特定的事件（例如刮胡子，去海滩）以及回忆著名的或个人熟悉的地方和人物。我们的发现揭示了两个关键的见解。首先，我们发现了一个明显的梯度表示从更多的感知相关的更多的记忆相关的从后到前MPC。第二，我们发现MPC中的不同细分在回忆人物或地点时是活跃的。 虽然人和地点是我们从记忆中回忆起的两个最重要的事情，但我们也可以回忆起特定的物体，并且在视觉皮层中已经确定了专门用于处理面部，场景和物体的独立区域。在后续的研究中，我们一直在探讨物体的回忆是否也会在MPC中招募一个单独的区域，以及物体和场景的回忆所引发的激活与对相同刺激的感知所引发的激活如何比较。 总的来说，这些结果为理解MPC的功能作用及其在认知的不同方面的意义提供了一个新的框架。 2)阐明场景记忆的内容 当我们回忆起以前经历过的事情时，我们到底记得什么？我们的记忆是对那件事的精确、高清晰度的记录，还是那件事的低清晰度的要点，或者甚至只是对我们所看到的东西的口头描述？回答这个问题是能够梳理记忆机制的一个重要组成部分：什么信息被编码和保存，记忆如何随着时间的推移而衰减，以及从这些记忆中提取什么信息。 在一系列的研究中，我们一直在调查的内容记忆真实的世界的场景使用绘图任务。参与者研究场景，然后在一段时间后，从记忆中尽可能详细地画出这些场景。由此产生的基于记忆的绘画由数千名在线观察者评分，揭示了许多对象，很少的记忆入侵和精确的空间信息。我们研究了年轻的志愿者以及声称没有视觉意象（称为aphantasia）的人。此外，我们还研究了一种常见的失真，发生在内存中的场景的边界是延长或收缩。 我们的研究结果表明，在自由回忆过程中，不仅可以量化记忆的内容，而且这些记忆包含了我们视觉体验的详细表征（尽管记忆失真仍然可能发生）。 阐明大脑如何使我们能够识别物体，场景，面孔和身体，为我们对周围世界的内部表征的本质提供了重要的见解。理解这些表征对于试图确定许多精神健康和神经系统疾病的潜在缺陷至关重要。