TCD Assessment of Hemovelocity while Older Adults Think

该研究计划有两个目标：(a)确定已知的调节年轻人脑血流速度的认知活动是否会引起老年人无中风者的类似变化，以及(b)记录老年人进行这些活动时出现的血流速度的时间过程调节。这些目标导致两个具体的目标：(1)验证个人认知活动的效果或。年轻人的速度和(2)记录了相同的认知活动对老年人的速度的影响，没有中风的人。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来记录人们进行认知活动时双侧脑血流速度。认知任务为日常思维活动建模，并将从短期记忆、设想角色体验、做出决策、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，在超声侧（右和左）和认知阶段（相关基线和特定任务）重复测量。研究人员对年轻人（实验1）和无中风的老年人（实验2）在大脑内执行7- 9,31秒的认知任务时的大脑中动脉进行了采样。一个30分钟的测试环节。第三个实验将通过增加脑动脉（中动脉、前动脉、后动脉）作为一个因素，扩展为三因素析因设计。研究人员将对同一位没有中风的老年人的动脉进行采样，以比较在认知活动中可能出现的相对流速差异。实现这两个目标将为从业者提供一系列认知探针，作为传统功能测试的辅助，以评估老年人（包括可能表现出脑血管功能障碍的老年人）对脑血管自动调节机制的时间弹性。

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.