Departments of Neurology and Physiology, WM Keck Foundation Center for Integrative Neuroscience, University of California, San Francisco, CA 94158, United States.
Neurobiol Aging. 2012 Jan;33(1):134-48. doi: 10.1016/j.neurobiolaging.2010.01.012. Epub 2010 Feb 9.
Interference is known to negatively impact the ability to maintain information in working memory (WM), an effect that is exacerbated with aging. Here, we explore how distinct sources of interference, i.e., distraction (stimuli to-be-ignored) and interruption (stimuli requiring attention), differentially influence WM in younger and older adults. EEG was recorded while participants engaged in three versions of a delayed-recognition task: no interference, a distracting stimulus, and an interrupting stimulus presented during WM maintenance. Behaviorally, both types of interference negatively impacted WM accuracy in older adults significantly more than younger adults (with a larger deficit for interruptions). N170 latency measures revealed that the degree of processing both distractors and interruptors predicted WM accuracy in both populations. However, while WM impairments could be explained by excessive attention to distractors by older adults (a suppression deficit), impairment induced by interruption were not clearly mediated by age-related increases in attention to interruptors. These results suggest that distinct underlying mechanisms mediate the impact of different types of external interference on WM in normal aging.
干扰已知会对工作记忆 (WM) 中信息的保持能力产生负面影响，这种影响随着年龄的增长而加剧。在这里，我们探讨了不同来源的干扰，即分心（需要忽略的刺激）和中断（需要注意的刺激），如何在年轻和老年成年人中对 WM 产生不同的影响。在参与者进行三种延迟识别任务的过程中记录了 EEG：无干扰、干扰刺激和在 WM 维持期间呈现的中断刺激。行为上，两种类型的干扰都显著地比年轻成年人对老年成年人的 WM 准确性产生更大的负面影响（中断的影响更大）。N170 潜伏期测量表明，在两种人群中，处理分心物和中断物的程度都可以预测 WM 的准确性。然而，虽然 WM 障碍可以通过老年成年人对分心物的过度关注来解释（抑制缺陷），但中断引起的障碍不能通过与年龄相关的对中断物的注意力增加来清楚地介导。这些结果表明，不同类型的外部干扰对正常衰老中 WM 的影响是由不同的潜在机制介导的。
