Everyone forgets things from time to time and problems with memory are experienced by most healthy adults as they age. Dr. Nancy Dennis, Assistant Professor of Psychology, College of the Liberal Arts, has received funding from the National Science Foundation (NSF) and the American Federation for Aging Research (AFAR) to extend current research on forgetfulness by examining “false” memories and intentional forgetting.
“By understanding how memory systems evolve as we age, we can gain a better understanding of what is underlying age-related deficits in memory performance. This will be critical to the implementation of memory and interventions and training,” said Dennis. “Also, as memory decline can be symptomatic of non-healthy aging, like in Alzheimer’s Disease, it is critical to be able to separate the natural development of memory across the lifespan from abnormal development, which may require specific interventions and treatment.”
In her research, Dennis uses both behavioral and brain imaging methods to investigate the ways in which memory systems function. SSRI seed funds facilitated Dennis’s collection of pilot data on false memories with the fMRI scanner at the Social, Life and Engineering Sciences Imaging Center (SLEIC) and led to the successful NSF application.
The focus of Dennis’s four-year NSF funded grant is false memories in aging. “We are testing a fuzzy trace theory, which proposes that older adults rely on remembering the gist of something, but not the item specifically,” said Dennis. She added that there is behavioral evidence for this theory, but very little neural evidence. Research using fMRI technology has further revealed age differences in the functional connectivity between various brain regions. “For instance, when compared to younger individuals, older adults tend to activate their frontal lobes significantly more when trying to remember. This suggests that, as we age, we engage in cognitive control, or employ purposeful strategies to remember things well,” said Dennis. The purposeful strategies used by older individuals appear to compensate for normal age-related reductions in neural functioning in other areas of the brain, such as the hippocampus, a part of the brain central to long-term memory.
Behavioral research has found that while older adults exhibit increased incidental forgetting (accidental forgetting of items individuals intend to remember), they exhibit decreased intentional or goal-directed forgetting (the strategic process of overtly trying to forget). Dennis’s AFAR grant supports the first investigation of the neural basis for one of the leading behavioral theories regarding age-related decline, the Inhibition Deficit Theory. Her research not only investigates the age-related differences in neural recruitment associated with incidental and intentional forgetting, but also addresses how brain regions involved in each process work together to accomplish task goals. This understanding of the neural basis that mediates memory differences across the lifespan is critical for explaining the difference between normal development changes and more severe disease-associated changes.
The benefit of fMRI technology in studying memory is that patterns of neural activity can be measured at the time of encoding (i.e., laying down the memory in the brain) and separately at the time of retrieval (i.e., calling up the memory when it is needed) making Dr. Dennis’s work highly innovative.