AGING AND INHIBITORY BEHAVIOR: AN FMRI STUDY

这项拟议研究的目标是使用功能磁共振成像(FMRI)来识别与老年人行为观察到的抑制缺陷相对应的大脑区域。关键的问题是，是否存在一个协调抑制行为的上位区域或系统，例如前额叶(West，1996)或额叶-皮质下环路(Alexander et al.，1986)。或者，抑制可以在每种反应方式中协调，并且不存在重叠的上级系统。可以假设，行为抑制包括抑制倾向于有意反应的优势/反身反应。第一系列实验将比较年轻人和老年人在不同抑制性任务中的功能激活重叠。第二个实验将测试年轻人和老年人在损害和促进抑制行为的条件下，特别是在昼夜节律唤醒周期的不同时间点。第三个实验将抑制行为与其他认知过程联系起来，通过比较根据工作记忆功能测试的表现选择的受试者的亚组。

The goal of the proposed studies is to use functional magnetic resonance imaging (fMRI) to identify brain regions corresponding to behaviorally observed inhibitory deficits in older adults. The critical question is whether there is one superordinate region or system which coordinates inhibitory behavior, such as the prefrontal lobes (West, 1996) or frontal-subcortical circuits (Alexander et al., 1986). Alternatively inhibition may be coordinated within each response modality and there is no overlapping superordinate system. It will be assumed that behavioral inhibition involves suppression of a prepotent/reflexive in favor of an intentional response. The first series of experiments will compare the overlap in functional activation for varied inhibitory tasks in young and elderly adults. The second experiments will test young and elderly adults under conditions which impair and facilitate inhibitory behavior, specifically at varying points in circadian the arousal cycle. The third experiment relates inhibitory behaviors to other cognitive processes by comparing subgroups of subjects that have been selected based on performance on a test of working memory functioning.