Age-related Individual Differences in Executive Control

这项研究评估了神经系统中与年龄相关的变化的个体差异，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，存在很大范围的可变性，例如，与年轻人相比，一些人保持相对完整的神经反应和行为表现，而另一些人则表现出损伤。这些与年龄相关的影响通常在涉及执行控制机制的任务中很明显，例如抑制不必要的反应

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.