Memory Monitoring and Declarative Memory: Behavior and Brain

Emory University, Atlanta GA

Investigators

Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): The human ability to consciously monitor the contents of memory has not been accessible to study in animal models. Memories that are accessible to monitoring are often called explicit or declarative. In contrast implicit or unconscious memories cannot be subjectively monitored, but are still evident in behavior. For example, a person who may not be able to verbally report the locations of the letters on a keyboard may nonetheless type accurately and rapidly without looking at the keys. The ability to monitor memory is a form of metacognition, which is impaired in autism, age-related cognitive decline, and attention and impulse control disorders such as ADHD. Loss of memory from stroke, Alzheimer?s disease, and other brain insults severely impairs higher cognitive processes including learning, planning, and adaptive decision-making. Animal models are needed to identify the specific brain structures involved in memory monitoring so that we can develop improved treatments for cognitive impairment in humans. In addressing these problems, the main challenge in the use of animal models is that animals cannot provide the verbal reports often used to identify memory monitoring in humans. To overcome this obstacle, we will implement new behavioral paradigms in which a ?decline test? option allows subjects to select which memory tests to take and which to avoid. Accurate memory monitoring is operationally defined as choosing to take tests when the item is remembered and avoiding tests when it is not remembered, thus providing a model of this crucial human capacity. The proposed work is the first to combine memory monitoring paradigms in an animal model with neuroanatomical techniques that will identify the neural basis of memories that are subject to monitoring. Because monitored and unmonitored memory operate simultaneously to produce adaptive behavior, the proposed studies are designed to determine how these memory types work together. Methodology called Process Dissociation Procedure is designed to quantify the simultaneous action of multiple memory systems and will be adapted from the human cognitive literature for use in the present project. I will use these new behavioral techniques to achieve three specific aims: 1) quantify the independent contributions of monitored and unmonitored memories to performance in memory tests, 2) determine whether monitored and unmonitored memories are neuroanatomically distinct, and 3) test the dual process/dual system theory of recognition memory performance. Development of this animal model system will advance work on the physiology, neurochemistry, and genetics of cognition and will contribute to the treatment of diseases affecting higher cognitive function. PUBLIC HEALTH RELEVANCE: This research is relevant to human health because it promises substantial progress in the study of memory in an important animal model of human cognition. Memory monitoring targets the type of memory most often compromised in stroke, Alzheimer's disease, and other brain insults affecting higher cognitive function. Development of this model system will permit further work on the physiology, neurochemistry, and genetics of memory that will contribute to the treatment of these devastating human conditions.