Age-related changes in electrophysiological and neuropsychological indices of working memory, attention control, and cognitive flexibility.
Age-related changes in electrophysiological and neuropsychological indices of working memory, attention control, and cognitive flexibility.
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DOI：
10.3389/fpsyg.2011.00190
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发表时间：
2011
影响因子：
3.8
通讯作者：
Fabiani M
中科院分区：
文献类型：
--
作者：
Peltz CB;Gratton G;Fabiani M
老年人的认知能力表现出很大的差异，一些人在执行控制任务上保持高水平的表现，而另一些人则表现出明显的缺陷。先前的事件相关电位（ERP）研究表明，其中一些表现差异与老年人由任务相关事件引起的新颖性/额叶 P3 的持续存在相关，这可能反映了抑制对意外但不再新颖的事件的定向能力的可变性。在最近针对年轻人的 ERP 工作中，我们表明，操作跨度 (OSPAN) 任务（注意力控制的一种衡量标准）可以预测个体跟踪刺激顺序和维持任务刺激的运行心理表征的能力，如顶叶分布的 P300（或 P3b）所索引。这两种现象都反映了额叶功能的各个方面（分别是认知灵活性和注意力控制）。为了研究这些现象，我们将年轻人和老年人分为低工作记忆广度和高工作记忆广度以及低认知灵活性和高认知灵活性亚组，并在等概率选择反应时任务中检查 ERP。对于两个年龄组，(a) OSPAN 得分高的参与者能够更好地跟踪刺激顺序，如他们较小的 P3b 顺序变化所示； (b) 认知灵活性较低的参与者比高分参与者的 P3a 更大。然而，这两种现象并没有相互作用，表明它们表现出可分离的控制机制。此外，这两种影响在年轻人中已经可见，这一事实表明，认知衰老个体差异背后的至少一些大脑机制可能已经在生命早期发挥作用。
Older adults exhibit great variability in their cognitive abilities, with some maintaining high levels of performance on executive control tasks and others showing significant deficits. Previous event-related potential (ERP) work has shown that some of these performance differences are correlated with persistence of the novelty/frontal P3 in older adults elicited by task-relevant events, presumably reflecting variability in the capacity to suppress orienting to unexpected but no longer novel events. In recent ERP work in young adults, we showed that the operation-span (OSPAN) task (a measure of attention control) is predictive of the ability of individuals to keep track of stimulus sequencing and to maintain running mental representations of task stimuli, as indexed by the parietally distributed P300 (or P3b). Both of these phenomena reflect aspects of frontal function (cognitive flexibility and attention control, respectively). To investigate these phenomena we sorted both younger and older adults into low- and high-working memory spans and low- and high-cognitive flexibility subgroups, and examined ERPs during an equal-probability choice reaction time task. For both age groups (a) participants with high OSPAN scores were better able to keep track of stimulus sequencing, as indicated by their smaller P3b to sequential changes; and (b) participants with lower cognitive flexibility had larger P3a than their high-scoring counterparts. However, these two phenomena did not interact suggesting that they manifest dissociable control mechanisms. Further, the fact that both effects are already visible in younger adults suggests that at least some of the brain mechanisms underlying individual differences in cognitive aging may already operate early in life.