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

描述（由申请人提供）：我们的视觉世界充满了物体的集群（或集合）。对于许多视觉任务，比如关注和选择特定的物体来进行思考或行动，我们需要从单个物体中个性化和编码独特的特征。在过去的几十年里，这种特定对象的处理一直是认知和神经科学研究的核心。相反，也有很多情况下，我们的视觉系统从对象集合中提取汇总统计信息，而不详细地表示集合中的每个对象。这种对象集成表示可以帮助我们快速分割拥挤的视觉场景，并允许我们放大感兴趣的特定对象。因此，对象集成表示补充和指导对象特定处理，并允许我们的视觉系统克服对象特定处理的容量限制。然而，尽管物体集成在我们的视觉世界中很常见，但对物体集成处理的认知和神经机制仍然知之甚少。利用功能磁共振成像技术，本研究将首先确定人脑中物体集合的表征位置，以及在何种注意条件下可以形成这种表征，然后通过研究集合特征的均值和方差如何表征来检验神经物体集合表征的本质。这项提议的研究将是第一个系统地研究现实世界的物体组合是如何在人脑中处理的。这些研究结果除了进一步加深我们对大脑与行为之间联系的理解外，还将对当前视觉客体感知的认知和神经理论产生重大影响。

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.