Johnson Jeffrey S, Simmering Vanessa R, Buss Aaron T
Department of Psychology and Center for Visual and Cognitive Neuroscience, North Dakota State University, Dept. 2765, P.O. Box 6050, Fargo, North Dakota, 58108-6050, USA,
Atten Percept Psychophys. 2014 Aug;76(6):1630-54. doi: 10.3758/s13414-013-0596-9.
Research over the past decade has suggested that the ability to hold information in visual working memory (VWM) may be limited to as few as three to four items. However, the precise nature and source of these capacity limits remains hotly debated. Most commonly, capacity limits have been inferred from studies of visual change detection, in which performance declines systematically as a function of the number of items that participants must remember. According to one view, such declines indicate that a limited number of fixed-resolution representations are held in independent memory "slots." Another view suggests that such capacity limits are more apparent than real, but emerge as limited memory resources are distributed across more to-be-remembered items. Here we argue that, although both perspectives have merit and have generated and explained impressive amounts of empirical data, their central focus on the representations--rather than processes--underlying VWM may ultimately limit continuing progress in this area. As an alternative, we describe a neurally grounded, process-based approach to VWM: the dynamic field theory. Simulations demonstrate that this model can account for key aspects of behavioral performance in change detection, in addition to generating novel behavioral predictions that have been confirmed experimentally. Furthermore, we describe extensions of the model to recall tasks, the integration of visual features, cognitive development, individual differences, and functional imaging studies of VWM. We conclude by discussing the importance of grounding psychological concepts in neural dynamics, as a first step toward understanding the link between brain and behavior.
过去十年的研究表明，将信息保存在视觉工作记忆（VWM）中的能力可能仅限于三到四个项目。然而，这些容量限制的确切性质和来源仍存在激烈争论。最常见的是，容量限制是从视觉变化检测研究中推断出来的，在这类研究中，随着参与者必须记住的项目数量的增加，表现会系统性下降。根据一种观点，这种下降表明在独立的记忆“插槽”中保存着数量有限的固定分辨率表征。另一种观点则认为，这种容量限制更多是表面现象而非实际存在，而是在有限的记忆资源分配到更多要记忆的项目时出现的。在这里，我们认为，尽管这两种观点都有其价值，并且已经产生并解释了大量令人印象深刻的实证数据，但它们对VWM背后的表征而非过程的核心关注，最终可能会限制该领域的持续进展。作为一种替代方案，我们描述了一种基于神经基础、基于过程的VWM方法：动态场理论。模拟表明，该模型不仅可以解释变化检测中行为表现的关键方面，还能产生已通过实验得到证实的新行为预测。此外，我们还描述了该模型在回忆任务、视觉特征整合、认知发展、个体差异以及VWM功能成像研究方面的扩展。我们在结论中讨论了将心理概念建立在神经动力学基础上的重要性，这是理解大脑与行为之间联系的第一步。
