Representing object ensembles in the human brain: Where, when and what

描述(申请人提供)：我们的视觉世界充满了物体的集群(或整体)。对于许多视觉任务，比如注意和选择特定的对象来思考或行动，我们需要从单个对象中对不同的特征进行个性化和编码。在过去的几十年里，这种特定对象的加工一直是认知科学和神经科学研究的核心。相比之下，我们的视觉系统也有充分的机会从对象集合中提取汇总统计数据，而不是非常详细地表示集合中的每个对象。这样的对象集合表示可以帮助我们快速分割原本拥挤的视觉场景，并允许我们放大感兴趣的特定对象。因此，对象集成表征是对特定对象处理的补充和指导，并允许我们的视觉系统克服特定对象处理的能力限制。然而，尽管物体集合在我们的视觉世界中普遍存在，但物体集合加工背后的认知和神经机制仍然知之甚少。使用功能磁共振成像，这一建议将首先确定对象集合在人脑中的哪里被表示，这种表示可以在什么注意条件下形成，然后通过研究集合特征的均值和方差是如何表示的来检查神经对象集合表示的性质。这项拟议的研究将是第一批系统地研究现实世界中的物体集合是如何在人脑中处理的研究之一。除了加深我们对大脑和行为之间联系的理解外，这些研究的结果还将对当前关于视觉物体知觉的认知和神经理论产生重大影响。 公共卫生相关性：拟议的研究将帮助我们了解正常视觉认知中的各种约束和限制。这对于理解脑损伤对视觉对象知觉和识别的影响也具有重要意义。

DESCRIPTION (provided by applicant): Our visual world is filled with clusters (or ensembles) of objects. For many visual tasks, such as attending and selecting specific objects for thoughts or actions, we need to individuate and encode distinctive features from single objects. Such object-specific processing has been the core of cognitive and neuroscientific research for the past few decades. In contrast, there are also ample occasions when our visual system extracts summary statistics from an object ensemble without representing each object in the ensemble in great detail. Such object-ensemble representation can help us rapidly segment an otherwise crowded visual scene and allow us to zoom in on specific objects of interest. Object-ensemble representation thus complements and guides object- specific processing and allows our visual system to overcome the capacity limitation of object-specific processing. Yet despite the common occurrence of object ensembles in our visual world, the cognitive and neural mechanisms underlying object-ensemble processing remains poorly understood. Using fMRI, this proposal will first identify where in the human brain object ensembles are represented, under what attentional condition this representation can be formed, and then examine the nature of the neural object ensemble representation by studying how mean and variance of ensemble features are represented. The proposed studies will be one of the first to systematically investigate how real world object ensembles are processed in the human brain. Besides furthering our understanding of the connection between brain and behavior, results of these studies will have significant impact on current cognitive and neural theories on visual object perception. PUBLIC HEALTH RELEVANCE: The proposed research will help us understand the various constrains and limitations in normal visual cognition. It also has significant implications for understanding the impact of brain damage on visual object perception and recognition.