Peira Nathalie, Ziaei Maryam, Persson Jonas
Department of Psychology, Uppsala University, Box 1225, 751 42 Uppsala, Sweden; Department of Psychology, Stockholm University, 106 91 Stockholm, Sweden.
School of Psychology, The University of QLD, St Lucia, QLD 4072, Australia.
Neuroimage. 2016 Jan 15;125:745-755. doi: 10.1016/j.neuroimage.2015.10.075. Epub 2015 Oct 28.
In prospective memory (PM), an intention to act in response to an external event is formed, retained, and at a later stage, when the event occurs, the relevant action is performed. PM typically shows a decline in late adulthood, which might affect functions of daily living. The neural correlates of this decline are not well understood. Here, 15 young (6 female; age range=23-30years) and 16 older adults (5 female; age range=64-74years) were scanned with fMRI to examine age-related differences in brain activation associated with event-based PM using a task that facilitated the separation of transient and sustained components of PM. We show that older adults had reduced performance in conditions with high demands on prospective and working memory, while no age-difference was observed in low-demanding tasks. Across age groups, PM task performance activated separate sets of brain regions for transient and sustained responses. Age-differences in transient activation were found in fronto-striatal and MTL regions, with young adults showing more activation than older adults. Increased activation in young, compared to older adults, was also found for sustained PM activation in the IFG. These results provide new evidence that PM relies on dissociable transient and sustained cognitive processes, and that age-related deficits in PM can be explained by an inability to recruit PM-related brain networks in old age.
在前瞻性记忆（PM）中，个体形成、保留对外部事件做出反应的意图，并在该事件发生的后期执行相关行动。PM通常在成年后期会出现衰退，这可能会影响日常生活功能。这种衰退的神经关联尚不清楚。在此，对15名年轻人（6名女性；年龄范围=23 - 30岁）和16名老年人（5名女性；年龄范围=64 - 74岁）进行功能磁共振成像扫描，以使用一项有助于分离PM的瞬态和持续成分的任务，研究与基于事件的PM相关的大脑激活的年龄差异。我们发现，在对前瞻性和工作记忆要求较高的情况下，老年人的表现有所下降，而在要求较低的任务中未观察到年龄差异。在所有年龄组中，PM任务表现激活了用于瞬态和持续反应的不同脑区集合。在额纹状体和内侧颞叶区域发现了瞬态激活的年龄差异，年轻人比老年人表现出更多的激活。与老年人相比，年轻人在额下回持续PM激活方面也表现出增加的激活。这些结果提供了新的证据，表明PM依赖于可分离的瞬态和持续认知过程，并且PM中与年龄相关的缺陷可以通过老年人无法募集与PM相关的脑网络来解释。
