BEHV AND IMAGING APPROCHES TO IMPLICIT MEMORY IN AGING

我们提出了一个精心整合和理论动机的行为和神经影像学研究，旨在扩大和深化目前的理解与年龄相关的内隐记忆的变化。 大多数研究表明，内隐记忆在实际年龄和年龄组内的时间上都是保留的，而外显记忆在老年受试者中会下降。然而，一些挑衅性的研究结果已经报道，显示内隐记忆丧失与某些类型的刺激，并超过时间延迟。 使用一个可能/不可能的对象决策启动任务，我们发现，决策准确性显着促进或启动的研究，但不为非研究可能的对象在年轻和老年人的科目。 然而，年轻的受试者继续显示启动长达1周后的研究，而启动几乎消失后20分钟的老年人。 老年人知觉记忆系统退化的暗示构成了我们所提出的工作的中心主题。 特别是，要解决的假设是，熟悉的或预先存在的表示可以被老年人内隐地记住，而新的表示的内隐记忆可能会随着时间的推移而恶化。 我们的策略将是建立行为方法和行为研究的结果，然后尝试探索支持这些任务的神经基质与后续的H215 O PET研究。 因此，从第一年开始，我们将进行一系列的6个行为实验，旨在测试我们的假设，最终在一项研究中，我们将使用一个训练程序，试图诱导熟悉我们的新刺激，以直接改善老年人的延迟内隐记忆表现。从第2年开始，我们将进行一系列PET研究，以跟进行为研究，并评估支持年轻人和老年人内隐记忆编码和提取的神经基质。该提案代表了合作者专业知识的独特组合，将为我们理解与年龄相关的记忆变化做出重大贡献。

We propose a carefully integrated and theoretically-motivated set of behavioral and neuroimaging studies designed both to broaden and deepen current understanding of age-related changes in implicit memory. Most studies report that implicit memory is preserved over chronological age as well as across time within an age group, whereas explicit memory declines in elderly subjects. However, some provocative findings have been reported, showing implicit memory loss with certain types of stimuli, and over temporal delays. Using a possible/impossible object decision priming task, we found that decision accuracy was significantly facilitated or primed for studied, but not for non-studied possible objects in both young and elderly subjects. However, young subjects continued to show priming up to 1 week after study, whereas priming virtually disappeared for the elders after 20 minutes. This suggestion of a deteriorating perceptual memory system in the elderly constitutes a central theme in our proposed work. In particular, the hypothesis to be addressed is that familiar or pre-existing representations can be remembered implicitly by older individuals; whereas implicit memory for novel representations may deteriorate over time. Our strategy will be to establish behavioral methodology and findings with behavioral studies, and then to attempt to explore the neural substrates that support these tasks with followup H215O PET studies. Thus, beginning in year 1, we will conduct a series of 6 behavioral experiments designed to test our hypotheses, culminating in a study where we will use a training procedure to try to induce familiarity in our novel stimuli in order to directly improve delayed implicit memory performance in elders. Beginning in year 2, we will conduct a series of PET studies to follow up on the behavioral studies and assess the neural substrates supporting encoding and retrieval of implicit memory both immediately and at delays in young and older individuals. This proposal represents a unique combination of expertise across collaborators and will make a major contribution to our understanding of age-related changes in memory.