Age-related Individual Differences in Executive Control

这项研究评估了与年龄相关的神经系统变化的个体差异，因为它们与记忆的执行控制机制有关。先前的研究表明，在健康的老年人群体中，存在很大范围的变异性，使得一些个体与年轻人相比保留相对完整的神经反应和行为表现，而其他个体则显示出损伤。这些与年龄相关的影响在涉及执行控制机制的任务中通常很明显，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一个单一的潜在机制，上下文处理，这是受老化。使用神经心理学和行为措施的执行控制，这一建议试图确定那些老年人可能拥有完整的功能和那些可能会出现功能缺陷。 具有 本研究确定了完整功能障碍的老年人亚组，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年人群中个体差异的基础。具体来说，它检查了前扣带皮层，前额叶皮层和海马体的年龄相关的变化，以确定这些结构的差异是否与个体的表现差异有关。此外，本研究测试的假设，这些多巴胺能神经区域介导的一个单一的上下文处理机制的基础性能上看似不同的执行控制过程。 将比较抑制、冲突检测和源监测的指数，以确定它们是否激活类似的神经结构，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.