Mechanisms of working memory capacity limits and their development

描述（由申请人提供）：这是一个项目的第25年的重新提交，该项目调查了工作记忆（WM），即执行认知任务所需的少量记忆，如何随着小学和成年期的发展而增加。该提案的大部分内容都被重写，并将评论者的评论铭记在心。他们称赞过去的进步;它帮助建立了人类大脑的一个关键组成部分，一个与注意力相关的工作记忆（WM）的中心组成部分，仅限于几个有意义的单元或块。然而，审查人员强调了先前提案的两个一般性问题。(1)提出的研究没有足够的理论依据， 新的研究方向，和（2）研究方法被认为是太渐进，理论上不够大胆，没有突破过去的进展足够的新天地。作为回应，现在提出的研究有助于一个中心问题：什么是WM能力的发展增加的机制？尽管米勒（Miller，1956）从记忆中有意义组块的数量角度讨论了容量限制，但由于测量组块和区分工作记忆不同成分的容量非常困难，此后的研究者大多回避了这一话题。然而，组块容量是理解的关键，因为它可能决定人类思维的可允许的复杂性。将组块容量与其他进程隔离是一项引人注目且困难的成就，这一成就已经得到普及（例如，科万的综述，2001年，引用了1，800多次，指出了一种恒定容量机制）。到目前为止，我们的发展研究已经证明，在建立这样一个概念方面特别重要，即存在一种与其他记忆过程分离的核心工作记忆能力（例如，能够联合收割机组合项目以形成更大的块、排除分散注意力的信息、口头排练项目或以快速刷新它们）。仔细的发展调查可以突出一项技能的进步，而其他技能保持不变。尚未完成的是，首先，确定调查结果的普遍性。到目前为止，我们已经检查了容量与选择性注意和排练保持不变，只有视觉阵列探针识别，而我们已经检查了容量与组块形成保持不变，只有口头自由回忆。因此，我们的首要任务是确定在小学阶段发展起来的工作记忆能力是只包括特定领域的记忆库，还是也包括一个与注意力相关的核心工作记忆能力，这个能力可以在言语和视觉材料的识别和回忆测试中观察到。发展研究可以帮助我们理解核心容量限制如何依赖于注意力，项目是同时持有还是顺序刷新，以及核心工作记忆是否基于一定数量的项目或特征的保留。我们结合行为和神经成像方法和数学建模来理解正常的WM发展，因为它指导我们理解（1）认知发展和（2）我们如何治疗认知缺陷，即，哪些基本技能可能需要培训或其他补救措施。

DESCRIPTION (provided by applicant): This is a resubmission for a 25th year of a project investigating how working memory (WM), the small amount held in mind to carry out cognitive tasks, increases with development in the elementary school years and to adulthood. Much of the proposal has been rewritten with reviewers' comments taken to heart. They lauded the past progress; it helps establish a key component of the human mind, an attention-related, central component of working memory (WM) limited to a few meaningful units, or chunks. The reviewers, however, highlighted 2 general problems with the previously proposal. (1) There was insufficient theoretical rationale for the studies that were proposed, with an insufficiently clear new direction for the research, and (2) the research approach was perceived as too incremental and not theoretically bold enough, not breaking enough new ground beyond past progress. In response, the proposed research now contributes to one central question: What are the mechanisms of the developmental increase in WM capacity? Although Miller (1956) discussed capacity limits in terms of the number of meaningful chunks recalled, researchers since then have mostly avoided this topic because of the great difficulty of measuring chunks and distinguishing capacity from different components of WM. Yet, chunk capacity is critical to understand as it may determine the permissible complexity of human thought. Isolating chunk capacity from other processes has been a striking and difficult achievement, which has gained popularity (e.g., the review by Cowan, 2001, cited over 1,800 times, pointing to a constant-capacity mechanism). Our developmental investigations so far have proven especially important in establishing the notion that there is a core WM capacity that is separate from other mnemonic processes (e.g., the ability to combine items to form larger chunks, exclude distracting information, rehearse items verbally, or refresh them at a rapid rate). Careful developmental investigation can highlight the improvement in one skill with others held constant. What has not been accomplished yet is, first, to establish the generality of the findings. So far we have examined capacity with selective attention and rehearsal held constant only for visual array probe recognition, whereas we have examined capacity with chunk formation held constant only for verbal free recall. The first order of business is therefore to determine whether the WM faculties that develop during the elementary school years include only domain-specific stores, or also a central, attention-related, core WM faculty observable in tests of recognition and recall, i both verbal and visual materials. Developmental investigation can help us to understand how a core capacity limit is dependent on attention, whether items are held concurrently or refreshed sequentially, and whether a core WM is based on retention of a certain number of items or features. We incorporate behavioral and neuroimaging methods and math modeling to understand normal WM development, as it guides our understanding of (1) cognitive development and (2) how we might treat cognitive deficits, i.e., which basic skills might need training or other remediation.