TCD Assessment of Hemovelocity while Older Adults Think

这项研究计划以两个目标为指导：(A)确定已知的在年轻人中调节大脑血流速度的认知活动是否会在没有中风的老年人中引起类似的变化，以及(B)记录老年人进行这些活动时出现的血流速度的时程调节。这些目标导致两个具体目标：(1)验证个人认知活动的效果或。记录年轻人的运动速度，以及(2)记录相同的认知活动对没有中风的老年人运动速度的影响。为了实现这些目标，三个实验将使用经颅多普勒神经成像程序，在人进行认知活动时同时记录双侧脑血流速度。认知任务模拟日常思维活动，将从短期记忆、设想人物角色体验、做出决定、研究刺激和解决基于语言、非语言或定量的问题中选择。两个实验将遵循双向析因设计，在刺激侧(右和左)和认知阶段(相关基线和特定任务)上重复测量。年轻人(实验1)和没有中风的老年人(实验2)的大脑中动脉将在他们执行7到9，31秒的认知任务时进行采样。30分钟的测试会话。第三个实验将通过添加大脑动脉(中、前、后)作为一个因素，扩展到三向析因设计。同样年长、没有中风的人的动脉将被采样，以比较认知活动期间可能出现的相对速度差异。这两个目标的实现将为作为传统功能测试辅助工具的从业者提供一系列认知调查，以评估老年人对脑血管自动调节机制的时间弹性，包括那些可能表现出脑血管功能障碍的人。

This research plan is guided by two goals: (a) to determine if cognitive activities known to modulate cerebral hemovelocity in young adults induce comparable changes in older, stroke-free persons, and (b) to document time-course modulations in hemovelocity that emerge while older persons perform these activities. These goals lead to two specific objectives: (1) verify the effects of individual cognitive activities or. the velocities of younger persons, and (2) document the effects of the same cognitive activities on velocities of older, stroke-free persons. To accomplish these objectives, three experiments will use a transcranial Doppler neuroimaging procedure to record bilateral cerebral blood flow velocity simultaneously while persons perform cognitive activities. The cognitive tasks model day-to- day thinking activities and will be selected from short-term remembering, envisaging a persona experience, making decisions, studying stimuli, and solving problems that are language based, nonlanguage based, or quantitative. Two experiments will follow two-way factorial designs, with repeated measures on insonation side (right and left) and cognitive phases (relevant baselines and specific tasks). The middle cerebral artery of young adults (Experiment 1) and older, stroke-free persons (Experiment 2) will be sampled while they perform 7-to-9, 31-sec cognitive tasks within. a 30-min test session. The third experiment will expand to a three-way factorial design by adding cerebral arteries (middle, anterior, posterior) as a factor. The arteries of the same older, stroke-free persons will be sampled to compare relative velocity differences that may emerge during the cognitive activities. Attainment of the two goals will provide a repertoire of cognitive probes to practitioners serving as adjuncts to traditional functional tests in assessing the temporal resiliency to the cerebrovascular autoregulation mechanisms of older persons, including those who may show cerebrovascular dysfunction.