Van Snellenberg Jared X, Conway Andrew R A, Spicer Julie, Read Christina, Smith Edward E
Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA,
Cogn Affect Behav Neurosci. 2014 Mar;14(1):106-16. doi: 10.3758/s13415-013-0235-x.
The concept of capacity has become increasingly important in discussions of working memory (WM), in so far as most models of WM conceptualize it as a limited-capacity mechanism for maintaining information in an active state, and as capacity estimates from at least one type of WM task-complex span-are valid predictors of real-world cognitive performance. However, the term capacity is also often used in the context of a distinct set of WM tasks, change detection, and may or may not refer to the same cognitive capability. We here develop maximum-likelihood models of capacity from each of these tasks-as well as from a third WM task that places heavy demands on cognitive control, the self-ordered WM task (SOT)-and show that the capacity estimates from change detection and complex span tasks are not correlated with each other, although capacity estimates from change detection tasks do correlate with those from the SOT. Furthermore, exploratory factor analysis confirmed that performance on the SOT and change detection load on the same factor, with performance on our complex span task loading on its own factor. These findings suggest that at least two distinct cognitive capabilities underlie the concept of WM capacity as it applies to each of these three tasks.
在工作记忆（WM）的讨论中，容量概念变得越来越重要，因为大多数WM模型将其概念化为一种有限容量的机制，用于将信息保持在活跃状态，并且至少从一种WM任务——复杂广度任务——得出的容量估计是现实世界认知表现的有效预测指标。然而，“容量”一词也经常在一组不同的WM任务——变化检测——的背景下使用，它可能指代也可能不指代相同的认知能力。我们在此从这些任务中的每一个——以及从对认知控制有很高要求的第三个WM任务，即自我排序WM任务（SOT）——开发容量的最大似然模型，并表明变化检测任务和复杂广度任务的容量估计彼此不相关，尽管变化检测任务的容量估计与SOT的容量估计相关。此外，探索性因素分析证实，SOT和变化检测任务的表现负载于同一个因素，而我们复杂广度任务的表现负载于其自身的因素。这些发现表明，WM容量概念应用于这三个任务中的每一个时，至少有两种不同的认知能力作为其基础。
