Rachel Rac-Lubashevsky, Department of Brain and Cognitive Sciences and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Heleen A. Slagter, Brain and Cognition, Department of Psychology, and Amsterdam Brain and Cognition (ABC), University of Amsterdam, Amsterdam, The Netherlands.
Sci Rep. 2017 May 31;7(1):2547. doi: 10.1038/s41598-017-02942-3.
Effective working memory (WM) functioning depends on the gating process that regulates the balance between maintenance and updating of WM. The present study used the event-based eye-blink rate (ebEBR), which presumably reflects phasic striatal dopamine activity, to examine how the cognitive processes of gating and updating separately facilitate flexible updating of WM contents and the potential involvement of dopamine in these processes. Real-time changes in eye blinks were tracked during performance on the reference-back task, in which demands on these two processes were independently manipulated. In all three experiments, trials that required WM updating and trials that required gate switching were both associated with increased ebEBR. These results may support the prefrontal cortex basal ganglia WM model (PBWM) by linking updating and gating to striatal dopaminergic activity. In Experiment 3, the ebEBR was used to determine what triggers gate switching. We found that switching to an updating mode (gate opening) was more stimulus driven and retroactive than switching to a maintenance mode, which was more context driven. Together, these findings show that the ebEBR - an inexpensive, non-invasive, easy-to-use measure - can be used to track changes in WM demands during task performance and, hence, possibly striatal dopamine activity.
有效的工作记忆（WM）功能取决于门控过程，该过程调节 WM 的维持和更新之间的平衡。本研究使用基于事件的眨眼率（ebEBR），这可能反映了纹状体多巴胺的相位活动，以研究门控和更新这两个认知过程如何分别促进 WM 内容的灵活更新，以及多巴胺在这些过程中的潜在作用。在参考回溯任务中进行操作时，实时跟踪眨眼的实时变化，在此任务中，分别操纵了这两个过程的要求。在所有三个实验中，需要 WM 更新的试验和需要门切换的试验都与 ebEBR 的增加有关。这些结果可能通过将更新和门控与纹状体多巴胺能活动联系起来，支持前额叶皮层基底神经节 WM 模型（PBWM）。在实验 3 中，使用 ebEBR 来确定是什么触发了门切换。我们发现，切换到更新模式（开门）比切换到维持模式（更多的是上下文驱动）更受刺激驱动和回溯性驱动。总之，这些发现表明，ebEBR-一种廉价、非侵入性、易于使用的测量方法-可用于跟踪任务执行过程中 WM 需求的变化，从而可能追踪到纹状体多巴胺的活动。
