When “capacity” changes with set size: Ensemble representations support the detection of across-category changes in visual working memory
When “capacity” changes with set size: Ensemble representations support the detection of across-category changes in visual working memory
复制标题
当“容量”随设定大小变化时：集成表示支持检测视觉工作记忆中的跨类别变化
DOI：
10.1167/19.5.3
复制
发表时间：
2019
影响因子：
1.8
通讯作者：
Brady, Timothy F.
中科院分区：
文献类型：
--
作者：
Schurgin, Mark W.;Brady, Timothy F.
我们可以在脑海中积极地记住多少个物体，是否有一个固定的限制？一般来说，研究人员发现，如果少量物体较复杂，参与者的记忆能力就会较差，这表明有限的资源而不是固定数量的物体最能解释工作记忆的表现。然而，一些证据表明，刺激相似性可以更好地解释这些影响，并且在考虑了这种相似性之后，数据支持工作记忆的基于槽的固定项目限制。用于支持后一种说法的大部分证据依赖于包含不同类别项目的工作记忆显示。研究发现，对于较大的跨类别变化，不同类型的复杂刺激的表现没有差异。然而，许多这些研究未能充分控制集合信息在区分如此大的变化时的潜在用途。在这里，我们试图确定有多少集成表示可以解释这些任务的性能。在实验 1 中，我们观察到，随着集合大小从 4 个项目增加到 12 个项目，跨类别变化的容量估计也线性增加，这为反对固定容量的主张提供了证据。在实验 2 中，我们控制了刺激的复杂性和相似性，但改变了变化检测任务的集成表示的效用。我们观察到，当可以使用集合信息时，容量会显着提高。总而言之，这些结果与工作记忆容量上的槽状固定对象约束相反，并且与强烈影响工作记忆性能的对象复杂性和整体表示一致。
Is there a fixed limit on how many objects we can hold actively in mind? Generally, researchers have found participants are worse at remembering a small number of objects if those objects are more complex, suggesting a limited resource rather than a fixed number of objects best explains working memory performance. However, some evidence has suggested that stimulus similarity better accounts for these effects and that, after accounting for such similarity, the data support a slot-based fixed item limit for working memory. Much of the evidence used to support the latter claim relies on working memory displays containing different categories of items. It has been found that, for large, across-category changes, performance does not differ for different kinds of complex stimuli. However, many of these studies fail to adequately control for the potential use of ensemble information in discriminating such large changes. Here, we sought to identify how much ensemble representations may explain performance across these tasks. In Experiment 1, we observed that, as set size increased from four to 12 items, capacity estimates for across-category changes increased linearly as well, providing evidence against the claim of a fixed capacity. In Experiment 2, we controlled for stimulus complexity and similarity but varied the utility of ensemble representations for the change-detection task. We observed significantly greater capacity when ensemble information could be used. Altogether, these results are contrary to a slot-like, fixed-object constraint on working memory capacity and consistent with object complexity and ensemble representations strongly affecting working memory performance.