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。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。该项目将重点关注四个关键问题，即数量和分辨率因素如何决定WM容量。首先，我们将检查个体的数量和分辨率限制是刺激特异性的还是反映了更多的刺激一般限制。其次，我们将探讨个体如何自愿控制这两种有限内存资源的分配。第三，我们将衡量个人对可能目标位置的隐性知识如何影响WM能力的分配。最后，我们将使用神经成像数据的多体素模式分析（MVPA）来评估皮层的视觉感觉区域是如何被招募来帮助表征WM中的信息的，以及它们是否有助于确定个体的助记分辨率。因此，本研究的总体目标是更精细地表征WM中能力限制的本质，并进一步表征控制进入这一有限心理工作空间的机制。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。公共卫生相关性：提出的研究的核心目标是更好地表征人类工作记忆容量限制的性质。该记忆系统是大多数认知过程的核心部分，该系统的容量与流体智力和学业成就相关。由于工作记忆的中断在诸如多动症和精神分裂症等常见的临床疾病中很常见，因此更好地了解该系统的行为和神经基础将对涉及认知受损的精神病理学的诊断和治疗产生有益的影响。

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 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 project will focus on four critical questions regarding how the factors of number and resolution determine WM capacity. First, we will examine whether number and resolution limits for an individual are stimulus-specific or whether they reflect more stimulus-general limitations. Second, we will explore how individuals can voluntarily control the allocation of these two limited memory resources. Third, we will measure how an individual's implicit knowledge about likely target locations can influence the allocation of WM capacity. Finally, we will use multi-voxel pattern analysis (MVPA) on neuroimaging data to assess how visual sensory areas of cortex are recruited to help represent information in WM and whether they help to determine an individual's mnemonic resolution. Thus, the general goal of this research is to more finely characterize the nature of capacity limits in WM, and to further characterize the mechanisms that control access to this limited mental workspace. 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: The core goal of the proposed research is 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. Because disruptions of working memory are common in prevalent clinical disorders such as ADHD and schizophrenia, a better understanding of the behavioral and neural underpinning of this system will have a beneficial impact on both the diagnosis and treatment of psychopathologies that involve impaired cognition.