Neural mechanisms of age-related changes in perceptual and memory decisions

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Decision-making abilities change as we age. While some changes are beneficial, such as improvements arising from accumulated experience, others are not. For example, older people are typically more cautious than is optimal in their decision-making, and are less apt to altar their decision strategies even when it would be advantageous. These changes can affect our health and quality of life. Despite the importance of decision making to healthy living, the neural mechanisms of the decision-making process, from perception to action, and how those mechanisms change in aging, are poorly understood. With the support of the National Science Foundation, Dr. Mark Wheeler and his research team at the Georgia Institute of Technology will use functional magnetic resonance imaging (fMRI) to identify how age-related differences in decisions about what we perceive and remember correspond with changes in brain function. Dr. Wheeler's research strategy is to investigate decision making as a multi-stage process in which incoming information is analyzed, evidence relevant to choices are extracted from that information and accumulated over time, and a decision is reached when there is enough evidence. Different stages of the decision process have been found to have different fMRI activation profiles, making it possible to identify whether specific stages change in healthy aging. It is predicted that, as we age, certain aspects of this multi-stage process change while others do not, and that these changes will be related to functional changes in the brain. For example, the increased caution found in many older individuals should be associated with a greater accumulation of fMRI activation prior to a decision, while a decrease in the fidelity of information processing in memory and perception should be associated with slower rates of accumulating fMRI activation. The research will also use machine learning approaches to test the degree to which the timing and amount of fMRI activity predict decision outcome. By investigating changes in neural activity as decisions develop in time, this project will identify which neural processes are most important in reaching a decision, and which change the most as we age. Such knowledge will be useful in the development of strategies or methods to improve decision-making abilities in later years. This project will have broader impacts on health, science training, and outreach. The research will address issues related to human health and well-being, such as how decision-making abilities in people who are in good health differ from people with Alzheimer's disease. The research program emphasizes mentoring of high school, undergraduate, and graduate students in learning the scientific process, including hands-on training in hypothesis generation, experimental design, data collection, processing, analysis, and interpretation, and public speaking/presentation. Undergraduate researchers with advanced projects are encouraged to present their findings at local and international conferences. Research findings are presented in scientific and public formats, including scientific meetings and publications, web sites, classes, and community seminars and forums.