Age-related Individual Differences in Executive Control

这项研究评估了神经系统中年龄相关变化的个体差异，因为这些变化与执行控制记忆的机制有关。先前的研究表明，在健康的老年人群体中，存在着很大范围的变异性，以至于与年轻人相比，一些人保持了相对完整的神经反应和行为表现，而另一些人则表现出障碍。这些与年龄相关的效应在涉及执行控制机制的任务中往往很明显，例如抑制不想要的反应或 信息、冲突检测、源监控和干扰控制。最近，有人提出，这些不同类型的执行控制反映了单一的潜在机制，即背景加工，该机制受年龄的影响。这项提案使用执行控制的神经心理学和行为测量方法，试图识别哪些老年人可能拥有完整的功能，哪些可能经历功能缺陷。拥有 这项研究确定了老年人中有视觉功能障碍的亚群，使用功能磁共振成像和结构磁共振成像来测试特定的神经结构是否是老龄化人口中个体差异的根源。具体地说，它检查了前扣带回皮质、前额叶皮质和海马体中与年龄相关的变化，以确定这些结构的差异是否与个体表现的差异有关。此外，这项研究还检验了这样一种假设，即由这些多巴胺能神经区介导的单一背景加工机制是执行控制过程表现的基础。将比较抑制指数、冲突检测指数和来源监测指数，以确定它们是否激活了类似的神经结构，以及这些结构在多大程度上可以被认为是相关的电路。

This research assesses individual differencesin age-related changes in the neural system as they relate to mechanisms of executive control over memory. Prior research has shown that in groups of healthy older adults, there is a large range of variability such that some individuals retain relatively intact neural responses and behavioral performance compared to younger adults, while other individuals show impairments. These age-related effects are often apparent in tasks involving executive control mechanisms, such as inhibition of unwanted responsesor information, conflict detection, source monitoring, and control over interference. Recently, it has been suggested that these various types of executive control reflect a single underlying mechanism, contextual processing, that is affected by aging. Using neuropsychological and behavioral measures of executive control, this proposal attempts to identify those older adults likely to possess intact functioning and those likely to experience deficits infunction. Having identified subgroups of older adults who are intactor dysfunctional, this research uses fMRI and structural MRI to test whether specific neural structures underlie individual differences within the aging population. Specifically, it examines age-related changes in the anterior cingulate cortex, prefrontal cortex, and hippocampus to determine whether differences in these structures are related to individual variability in performance. Further, this research tests the hypothesis that a unitary contextual processing mechanism mediated by these dopaminergic neural areas underlies performance on seemingly disparate executive control processes. Indices of inhibition, conflict detection, and source monitoring will be compared to determine whether they activate similar neural structures and to what extent those structures can be considered a correlated circuit.