The flexibility of individuation and ensemble representation

描述（由申请人提供）：视觉工作记忆是一种基本的认知资源，对视觉空间推理、眼球运动指导和感知随时间的稳定性至关重要。以往对视觉工作记忆的研究大多集中在其容量限制上，普遍认为视觉工作记忆最多可以同时存储3到4个个性化对象的详细视觉信息。一个独立的研究机构专注于存储来自对象集合的平均特征的低分辨率表示（集成表示）的并行能力，但没有太多的工作探索两者之间的联系，它们通常被视为视觉研究中的单独主题。相比之下，拟议的研究评估了关于这两种视觉表征模式如何相互关联的两个相互竞争的假设。灵活表示模型预测，视觉系统可以灵活地在个性化和集合表示之间交替，在任何给定的时间选择最合适的表示类型。封装表示模型认为，这些表示模式是自动的、不灵活的，它们一直是并行发生的。所提出的研究评估了这两种模型，依靠记忆精度的行为和神经特征来确定在应该（在灵活表征模型下）倾向于存储集合而不是个体的条件下，个性化是否会减少（和集成表征增强）。这些研究将使用EEG/ERP来测量所谓的个性化的神经特征-对侧延迟活动（CDA），并将有助于揭示该信号是否真正反映了个性化的类物体表征，还是更灵活的、分层结构的表征。关键的是，拟议的研究旨在产生一个

DESCRIPTION (provided by applicant): Visual working memory is a fundamental cognitive resource, critical for visuospatial reasoning, guidance of eye movements, and the stability of perception over time. Much of the previous research on visual working memory has focused on its capacity limitations, with a general consensus that visual working memory can store detailed visual information from at most 3 or 4 individuated objects at any one time. A separate body of research has focused on a parallel capacity for storing lower-resolution representations of average features (ensemble representations) derived from collections of objects - but not much work has explored connections between the two, and they are often treated as separate topics in vision research. By contrast, the proposed research evaluates two competing hypotheses about how these two modes of visual representation relate to one another. The Flexible Representation model predicts that the visual system can flexibly alternate between individuation and ensemble representation, choosing, as it were, the type of representation most appropriate at any given time. The Encapsulated Representation model holds that these modes of representation are automatic and inflexible, with both occurring in parallel, all of the time. Te proposed studies evaluate these two models, relying on behavioral and neural signatures of memory precision to determine whether individuation is reduced (and ensemble representation enhanced) under conditions that should (under the Flexible Representation model) favor storing ensembles rather than individuals. These studies will use EEG/ERP to measure a purported neural signature of individuation - the contralateral delay activity (CDA), and will help reveal whether this signal truly reflects individuated object-like representations, or more flexible, hierarchically structured representations. Critically, the proposed studies are designed to yield a definitive result - confirming either the Flexible model or the Encapsulated model - and will represent a major advance in the visual memory literature in either case. These studies may also shed light on previously-documented visual processing deficits in autism spectrum disorder (ASD). Specifically, prior research has shown that ASD individuals have difficulty with global or holistic perception, but seem to be better than typically-developing individuals at tasks that involve narrow focus or precise representations of parts. If our studies confirm the Flexible Representation model, this would suggest a more fundamental impairment underlying these effects - ASD individuals may have impaired flexibility, individuating even when they should be forming ensemble representations. Finally, this research will provide the applicant with vital training in both visual memory and ERP research. While the applicant has previously studied visual attention and perception, he has not extensively studied visual working memory, nor has he previously done EEG/ERP research. Thus, both aspects of the project represent critical training that will broaden the scope of the applicant's research skillset.