Kessler Yoav, Baruchin Liad J, Bouhsira-Sabag Anat
Department of Psychology and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, 84105, Beer-Sheva, Israel.
Psychol Res. 2017 Jan;81(1):191-203. doi: 10.1007/s00426-015-0717-2. Epub 2015 Oct 20.
Theoretical models suggest that maintenance and updating are two functional states of working memory (WM), which are controlled by a gate between perceptual information and WM representations. Opening the gate enables updating WM with input, while closing it enables keeping the maintained information shielded from interference. However, it is still unclear when gate opening takes place, and what is the external signal that triggers it. A version of the AX-CPT paradigm was used to examine a recent proposal in the literature, suggesting that updating is triggered whenever the maintenance of the context is necessary for task performance (context-dependent tasks). In four experiments using this paradigm, we show that (1) a task-switching cost takes place in both context-dependent and context-independent trials; (2) task-switching is additive to the dependency effect, and (3) unlike switching cost, the dependency effect is not affected by preparation and, therefore, does not reflect context-updating. We suggest that WM updating is likely to be triggered by a simple mechanism that occurs in each trial of the task regardless of whether maintaining the context is needed or not. The implications for WM updating and its relationship to task-switching are discussed.
理论模型表明，维持和更新是工作记忆（WM）的两种功能状态，它们由感知信息与WM表征之间的一个门控机制控制。打开这个门控能使WM通过输入进行更新，而关闭它则能使维持的信息免受干扰。然而，门控何时打开以及触发它的外部信号是什么仍不清楚。采用了一种版本的AX-CPT范式来检验文献中最近的一项提议，该提议认为，只要任务执行需要维持情境（情境依赖任务），更新就会被触发。在使用该范式的四项实验中，我们发现：（1）在情境依赖和情境独立试验中都会出现任务切换成本；（2）任务切换与依赖效应是相加的；（3）与切换成本不同，依赖效应不受准备的影响，因此不反映情境更新。我们认为，WM更新可能由一种简单机制触发，该机制在任务的每次试验中都会发生，无论是否需要维持情境。文中讨论了其对WM更新的影响及其与任务切换的关系。
