Effects of Age on the Cognitive ERPD/Cardiac Wave Effect

描述（由申请人提供）：正常衰老导致各种认知领域的衰退，包括执行控制和记忆过程，这对成功执行许多日常任务至关重要。这些下降在不同人群中并不一致，这表明下降的速度可能是可变的。因此，识别使一些老年人能够保持其认知功能的因素是认知老化研究的重要目标。血液动力学证据表明，一些老年人可能能够通过“补偿”来应对下降，即，招募年轻人不使用的大脑区域和可能的心理过程。然而，补偿假说经常是在事后才被援引的，因此，在哪些人需要补偿、哪些条件和任务会引起补偿以及所涉过程的性质方面，它是模糊的。因此，为了更好地理解个体差异，我们使用认知储备假设，该假设认为储备因素（由智力状态，智商和社会经济地位，SES等代理指标衡量）可能使一些老年人能够比其他人更成功地承受认知下降的有害影响。因此，我们将补偿问题嵌入更大的认知储备领域。因此，拟议的研究重点是提供额外的信息，对下降的个体差异的原因和性质的认知过程时，从事补偿活动。认知储备的作用将通过将年轻人和老年人分类为储备因子低或高（即，智商和社会经济地位），并根据他们的情景记忆表现（低，高）。这将有助于确定认知储备的个体差异是否比任务表现的个体差异更好地解释补偿活动。为了提供有关补偿性大脑活动的特定认知过程的性质的信息，将对认知需求（一个可能导致个体在高水平上补偿的变量）进行参数化操纵。此外，在任务执行过程中的ERPs记录应提供这些补偿过程的性质的时间信息，并揭示了重要的信息，在这些阶段，他们帮助任务相关的过程。具体来说，一个主要目的是测试一系列假设，即记忆形成和提取过程中的补偿性大脑活动代表了认知控制过程的招募，可能是由前额叶皮层介导的，并在线对抗与年龄相关的大脑功能下降。ERP和性能数据将从年轻人（20-30岁），老年人（60-70岁）和老年人（71-85岁）中获得，这将有助于确定与年龄相关的下降轨迹。通过改变五个情景记忆任务中每一个任务所需的认知控制水平，从而增加认知控制过程的需要，我们将能够确定在我们的老年人样本中哪些类型的个体可能产生补偿性大脑活动，以及这种补偿将发生的情况。认知老化研究的一个重要目标是了解某些执行控制和情景记忆过程中与年龄相关的变化的机制，因为这些对大脑的成功老化至关重要。本项目旨在通过确定哪些特定的执行控制过程有助于记录良好的、与年龄相关的情景记忆下降来进一步推动这一奋进。适当的药理学和/或认知/行为疗法的最终发展可以使干预措施能够帮助老年人记忆和/或执行功能障碍，至少部分改善这些缺陷，过上更健康，更富有成效的生活，这是一个重要的社会目标。

DESCRIPTION (provided by applicant): Normal aging results in declines in a variety of cognitive domains, including executive-control and mnemonic processes, which are critical for successfully performing many everyday tasks. The fact that these declines are not uniform across persons suggests that the rate of decline is potentially alterable. Therefore, identifying the factors that enable some elders to preserve their cognitive function is an important goal of cognitive aging research. Hemodynamic evidence suggests that some aging individuals may be able to deal with declines by "compensating," i.e., recruiting brain regions and presumably mental processes not used by young adults. However, the compensation hypothesis is frequently invoked on a post hoc basis and is, therefore, vague in terms of which persons need to compensate, which conditions and tasks elicit compensation and the nature of the processes that are engaged. Therefore, to enable a better understanding of individual differences, we use the Cognitive Reserve hypothesis, which posits that reserve factors (measured by proxies such as intellectual status, IQ, and socio-economic status, SES) may enable some older adults to withstand the deleterious effects of cognitive decline more successfully than others. Hence, we embed the issue of compensation within the larger domain of cognitive reserve. Thus, the proposed studies focus on providing additional information on both the reason for individual differences in decline and the nature of the cognitive processes recruited when compensatory activity is engaged. The role of cognitive reserve will be assessed by categorizing young and older adults as either low or high on reserve factors (i.e., IQ and SES) and on the basis of their episodic memory performance (low, high). This will help determine whether individual differences in cognitive reserve account better for compensatory activity than individual differences in task performance. To provide information on the nature of the specific cognitive processes underlying compensatory brain activity, cognitive demand, a variable that might lead individuals to compensate at high levels, will be parametrically manipulated. Further, the recording of ERPs during task performance should provide timing information about the nature of these compensatory processes and reveal important information about the stages at which they aid task-related processes. Specifically, a major aim is to test a series of hypotheses that compensatory brain activity during memory formation and retrieval represents recruitment of cognitive-control processes, presumably mediated by the prefrontal cortex, and brought on line to counter age-related decline in brain function. ERP and performance data will be obtained from young (20-30), young-old (60-70) and old-old (71-85) adults, which will help determine the trajectory of age-related declines. By varying the level of cognitive control required in each of five proposed episodic memory tasks and, thereby, the need to increment cognitive-control processes, we will be able to determine which types of individuals within our older-adult samples are likely to produce compensatory brain activity and the circumstances under which such compensation will occur. PUBLIC HEALTH RELEVANCE An important goal of cognitive aging research is to understand the mechanisms underlying age-related changes in certain executive-control and episodic-memory processes because these are critical to the successful aging of the mind. This project is aimed at furthering this endeavor by determining which specific executive-control processes contribute to the well-documented, age-related declines in episodic memory. The eventual development of appropriate pharmacological and/or cognitive/behavioral therapies could enable interventions that would aid older adults with mnemonic and/or executive dysfunctions in, at least partially, ameliorating those deficits and living healthier, more-productive lives, an important societal goal.