Effects of Age on the Cognitive ERPD/Cardiac Wave Effect

描述(申请人提供)：正常衰老导致各种认知领域的下降，包括执行控制和助记过程，这是成功完成许多日常任务的关键。这些下降在不同人中并不是一致的，这一事实表明下降的速度可能是可变的。因此，找出使一些老年人能够保持其认知功能的因素是认知衰老研究的一个重要目标。血液动力学证据表明，一些上了年纪的人可能能够通过“补偿”来应对衰退，即招募年轻人没有使用的大脑区域和想必是心理过程。然而，补偿假设经常是在事后援引的，因此，就哪些人需要补偿、哪些条件和任务需要补偿以及所从事的过程的性质而言，补偿假设是模糊的。因此，为了更好地理解个体差异，我们使用了认知储备假说，该假说假设储备因素(通过智力状况、智商和社会经济地位等指标衡量)可能使一些老年人比其他老年人更成功地抵御认知衰退的有害影响。因此，我们将补偿问题嵌入到认知储备的更大领域中。因此，拟议的研究侧重于提供更多的信息，既包括个体差异下降的原因，也包括补偿活动进行时所引起的认知过程的性质。认知储备的作用将通过将年轻人和老年人在储备因素(即IQ和SES)上归类为低或高，并根据他们的情景记忆表现(低、高)来评估。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了补偿活动。为了提供有关代偿性大脑活动背后的特定认知过程的性质的信息，认知需求将被参数控制，认知需求是一个可能导致个人在高水平进行补偿的变量。此外，在任务执行期间记录事件相关事件应提供有关这些补偿过程的性质的时间信息，并揭示有关它们协助与任务有关的过程的阶段的重要信息。具体地说，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代偿性大脑活动代表认知控制过程的招募，可能是由前额叶皮质调节的，并被引入以对抗与年龄相关的大脑功能下降。ERP和绩效数据将从年轻人(20-30岁)、年轻人(60-70岁)和老年人(71-85岁)获得，这将有助于确定与年龄相关的下降轨迹。通过改变五个拟议的情节记忆任务中每一个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，哪些类型的人可能产生代偿性大脑活动，以及在什么情况下这种补偿将发生。公共健康相关性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背后的机制，因为这些过程对大脑的成功老化至关重要。这个项目的目的是通过确定哪些特定的执行控制过程有助于有据可查的、与年龄相关的情景记忆下降，从而进一步推动这一努力。最终开发出适当的药理和/或认知/行为疗法，可以帮助患有记忆力和/或执行功能障碍的老年人进行干预，至少部分改善这些缺陷，过上更健康、更有成效的生活，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.