Project 3 - Expectancy Effects in Aging & Alzheimer's

记忆增强剂的临床试验通常表明，在接受安慰剂的受试者组中，认知结果测量在最初的一到两个月内得到改善。这种改善可能与预期或安慰剂效应有关。这项发展研究的目的是开发一个可靠的，简单的实验模型，安慰剂对老年人的认知功能，有和没有AD，这种影响的特点和估计的效果大小。我们还将探讨可能预测效果的受试者特征以及增加效果的方法。40名健康老年人和40名轻度AD患者将被招募进行一项研究，他们被告知是关于鼠尾草提取物对 认知功能在部分研究期间，将给予受试者2周的药丸，告知他们是S。药用植物将在服药2周后立即进行的访视与未服药2周后进行的访视之间比较认知功能。两种情况之间的差异将用作安慰剂效应的标志。认知评估包括标准临床量表和更多的实验性测量。本研究将确定安慰剂给药后认知功能的变化是否与以下因素相关：情绪和压力的变化;通过一般和记忆特异性自我效能量表评估的自我效能;通过EEG和自我评定量表评估的警觉性，以及与精神努力相关的电生理测量（EEG额叶中线θ）。我们相信，一些安慰剂效应是通过警觉性，情绪，自我效能和精神努力的变化来介导的 这可能是预期（安慰剂）效应的常见介质。此外，我们将探讨认知评估过程中的积极反馈是否会提高自我效能，以及自我效能是否会改变安慰剂对认知表现的影响。最后，我们将探讨是否有预测谁是最有可能表现出安慰剂效应：基因分型多态性影响神经递质和其他信号系统可能参与安慰剂效应;和评估人格特质与自我评定量表和他们可能相关的电生理标志物，特别注意那些特质也与这些信号系统。

Clinical trials of memory enhancing agents often demonstrate an improvement in cognitive outcome measures in the first one to two months in groups of subjects who received placebo. It is likely that some of this improvement is related to an expectancy or placebo effect. The goal of this developmental research is to develop a reliable, uncomplicated experimental model of placebo effect on cognitive function in older adults with and without AD, characterize this effect and estimate the effect size. We will also explore subject characteristics that may predict the effect and ways to increase the effect. 40 healthy seniors and 40 people with mild AD will be recruited for a study they are told is on the effects of an extract of Salvia officinalis on cognitive function. During part of the study, subjects will be given pills for 2 weeks that they are told is S. officinalis. Cognitive function will be compared between visits immediately following 2 weeks of pill taking and after 2 weeks of not taking any pills. The difference between the two conditions will be used as a marker for placebo effect. Cognitive assessments include standard clinical scales and well as more experimental measures. The study will determine if changes in cognitive function following administration of placebo correlate with: changes in mood and stress; self-efficacy as assessed by general and memory-specific self-efficacy scales; alertness as assessed by EEG and self-rated scales, and an electrophysiologic measure that relates to mental effort (the EEG frontal midline theta). We believe that some of the placebo effect is mediated through changes in alertness, mood, self-efficacy and mental effort that may be common mediators of the expectancy (placebo) effect. Additionally, we will explore whether positive feedback during cognitive assessments improves self-efficacy and whether self-efficacy alters placebo effects on cognitive performance. Lastly, we will explore whether there are predictors of who is most likely to demonstrate placebo effects by: genotyping for polymorphisms affecting neurotransmitter and other signaling systems potentially involved in the placebo effect; and assessing personality traits with self-rating scales and their possibly related electrophysiological markers, paying particular attention to those traits which have also been associated with these signaling systems.