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组中，在最初的一到两个月里，认知结果测量结果有所改善。这种改善很可能部分与预期或安慰剂效应有关。这项发展研究的目标是开发一个可靠的、简单的安慰剂效应对患有和不患有AD的老年人认知功能影响的实验模型，表征这种效应并估计其影响大小。我们还将探索可以预测效果的主题特征和增加效果的方法。40名健康老年人和40名轻度阿尔茨海默病患者将被招募参加一项研究，他们被告知丹参提取物对 认知功能。在研究的一部分，受试者将被给予两周的药片，他们被告知是药用沙门氏菌。认知功能将在服药2周后立即就诊和不服药2周后进行比较。这两种情况之间的差异将被用作安慰剂效果的标志。认知评估包括标准的临床量表和更多的实验措施。这项研究将确定服用安慰剂后认知功能的变化是否与以下方面相关：情绪和压力的变化；通过一般自我效能量表和记忆特定自我效能量表评估的自我效能；通过脑电和自我评估量表评估的警觉性；以及与精神努力有关的电生理指标(脑电前额中线theta)。我们认为，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调节的。 这可能是预期(安慰剂)效应的常见调节因素。此外，我们将探索认知评估中的正反馈是否提高了自我效能感，以及自我效能感是否改变了认知表现的安慰剂效应。最后，我们将探索是否存在预测谁最有可能表现出安慰剂效应的因素：影响神经递质和其他可能参与安慰剂效应的信号系统的基因分型；以及使用自我评定量表及其可能相关的电生理标记物评估人格特征，特别关注与这些信号系统相关的那些特征。

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.