The Distinction Between Number and Resolution in Visual Working Memory

描述（由申请人提供）：工作记忆（WM）是一种用于维护信息在线表征的系统，服务于几乎所有的外显认知过程（例如，记忆检索，解决问题）。WM在认知中的核心作用也被强调为WM能力和流体智力之间的强相关性，作为各种学术成就的衡量标准。此外，WM表现的缺陷与常见的临床疾病有关，包括注意缺陷/多动障碍（ADHD）和精神分裂症。本补充申请的母基金中拟议的研究将解决有关WM能力限制的基本决定因素的基本问题。容量是否受到可同时在WM中表示的项目的最大数量的限制？或者它是否受到表示一组给定项目所需的可用助记符分辨率（即清晰度）的限制？我们的初步数据表明，数量和分辨率不是由单一因素决定的，而是WM能力的不同方面。该研究旨在通过心理物理程序、人体电生理记录（ERPs）和使用FMRI的新型神经解码技术的结合，进一步详细说明这两个因素如何相互作用以限制WM的表现。这个补充应用程序通过大规模的个体差异研究扩展了母项目的范围，该研究检查了WM能力与流体智力标准测量（例如，斯坦福比奈智商）之间关系的本质。鉴于WM能力和流体智力之间的联系是WM研究的核心激励因素，因此，能够阐明为什么这些联系首先存在的研究具有很高的价值。我们的初步研究结果表明，虽然在WM中可以保留的表征的数量强有力地预测了流体智力，但这些记忆的精度或分辨率与智力没有相关性。我们将使用更广泛的记忆和智力的行为和神经测量来复制和扩展这一结果，目的是更好地理解低级记忆过程如何支持智能行为。该项目将告知WM如何在不同刺激模式下组织的认知模型，以及影响个体流体智力变化的WM功能的确切方面。更好地理解这些基础研究问题将有助于更准确地描述涉及认知加工受损的精神病理学，从而支持心理健康领域的基础研究和转化研究。

DESCRIPTION (provided by applicant): Working memory (WM) is a system for maintaining online representations of information in the service of virtually all explicit cognitive processes (e.g., memory retrieval, problem solving). WM's core role in cognition is also highlighted by strong correlations between WM capacity and fluid intelligence as various measures of scholastic achievement. Furthermore, deficits in WM performance are associated with prevalent clinical disorders, including attention deficit/ hyperactivity disorder (ADHD) and schizophrenia. The proposed research in the parent grant to this supplemental application will address fundamental questions regarding the basic determinants of capacity limits in WM. Is capacity limited by a maximum number of items that can be represented simultaneously in WM? Or is it limited by the available mnemonic resolution (i.e., clarity) necessary for representing a given set of items? Our preliminary data suggest that rather than being determined by a single factor, number and resolution are distinct facets of WM capacity. The proposed research seeks to further detail how these two factors interact to limit WM performance by means of a combination of psychophysical procedures, human electrophysiological recordings (ERPs), and novel neural decoding techniques using FMRI. This supplemental application expands the scope of the parent project by means of a large- scale individual differences study that examines the nature of the relationship between WM capacity and standard measures of fluid intelligence (e.g., Stanford Binet IQ). Given that the link between WM capacity and fluid intelligence is a core motivating factor for WM research, high value is placed on research that can elucidate why these links are present in the first place. Our preliminary findings indicate that while the number of representations that can be held in WM strongly predicts fluid intelligence, the precision or resolution of those memories showed no correlation with intelligence. We will replicate and extend this result using a broader range of behavioral and neural measures of memory and intellectual ability, with the goal of better understanding how intelligent behavior is supported by lower level memory processes. This project will inform both cognitive models of how WM is organized across stimulus modalities, and the precise aspects of WM function that influence individual variations in fluid intelligence. A better understanding of these basic research questions will enable a more precise characterization of psychopathologies that involve impaired cognitive processing, supporting both basic and translational research in the domain of mental health. PUBLIC HEALTH RELEVANCE: This proposal outlines a supplemental project that expands the scope of a parent grant project whose broad aims are to better characterize the nature of capacity limits in human working memory. This memory system is a core part of most cognitive processes, and capacity in this system is correlated with fluid intelligence and scholastic achievement. The supplemental proposal focuses on the relationship between working memory and fluid intelligence, following up on preliminary findings that while the number of items a person can maintain in working memory strongly predicts fluid intelligence, no such relationship was observed between the precision of the stored memories and intelligence. Given that the relationship between working memory and broad measures of intellectual ability constitute a core motivation for research in this area, a better understanding of how basic memory processes support intelligent behavior is highly desirable. The proposed research accomplishes this goal by characterizing why the number of items that can be stored in working memory relates to fluid intelligence, and providing further evidence on the broad taxonomy of visual working memory.