Tagliabue Chiara F, Mazza Veronica
Center for Mind/Brain Sciences (CIMeC) - University of Trento, Rovereto, Italy.
Front Psychol. 2021 Oct 18;12:753423. doi: 10.3389/fpsyg.2021.753423. eCollection 2021.
A reduction in cognitive resources has been originally proposed to account for age-related decrements in several cognitive domains. According to this view, aging limits the pool of available cognitive supplies: Compared to younger adults, elderly exhaust the resources more rapidly as task difficulty increases, hence a dramatic performance drop. Neurophysiological indexes (e.g., BOLD response and EEG activity) may be instrumental to quantify the amount of such cognitive resources in the brain and to pinpoint the stage of stimulus processing where the decrement in age-related resources is evident. However, as we discuss in this mini-review, the most recent studies on the neurophysiological markers of age-related changes lack a consistent coupling between neural and behavioral effects, which casts doubt on the advantage of measuring neural indexes to study resource deployment in aging. For instance, in the working memory (WM) domain, recent cross-sectional studies found varying patterns of concurrent age-related brain activity, ranging from equivalent to reduced and increased activations of old with respect to younger adults. In an attempt to reconcile these seemingly inconsistent findings of brain-behavior coupling, we focus on the contribution of confounding sources of variability and propose ways to control for them. Finally, we suggest an alternative perspective to explain age-related effects that implies a qualitative (instead of or along with a quantitative) difference in the deployment of cognitive resources in aging.
最初有人提出认知资源的减少可解释多个认知领域中与年龄相关的衰退。根据这一观点，衰老限制了可用认知资源的储备：与年轻人相比，老年人随着任务难度的增加会更快耗尽资源，因此表现会大幅下降。神经生理学指标（如血氧水平依赖反应和脑电图活动）可能有助于量化大脑中此类认知资源的数量，并确定与年龄相关的资源减少明显的刺激处理阶段。然而，正如我们在本综述中所讨论的，最近关于与年龄相关变化的神经生理学标志物的研究缺乏神经和行为效应之间的一致耦合，这使得测量神经指标以研究衰老过程中资源分配的优势受到质疑。例如，在工作记忆领域，最近的横断面研究发现了与年龄相关的并发脑活动的不同模式，从与年轻人相当到老年人激活减少和增加不等。为了调和这些看似不一致的脑-行为耦合研究结果，我们关注变异性混杂来源的影响，并提出控制这些影响的方法。最后，我们提出一种替代观点来解释与年龄相关的效应，这意味着衰老过程中认知资源分配存在质的差异（而非数量差异，或除数量差异外还存在质的差异）。
