Dr. Michael Rugg

“We are excited to have received this support, which will enable us to take our research in memory and aging in new and innovative directions,” said Dr. Michael Rugg (top), director of the Center for Vital Longevity.

Dr. Michael Rugg, director of UT Dallas’ Center for Vital Longevity, has been awarded nearly $1 million in grants to study how young and older adults remember specific events.

A three-year National Science Foundation (NSF) award for $544,000 will support research on episodic memory, or memory of specific events. An additional $421,000 comes from the National Institute on Aging (NIA) and covers research for two years on an aspect of memory known as “post-retrieval monitoring.”

Episodic memory is highly vulnerable to aging. Using functional magnetic resonance imaging (fMRI), Rugg and his colleagues will examine brain activity associated with episodic memory retrieval in groups of young and older adults.

“Current research shows that although the accuracy of episodic memory is highly age-sensitive, the subjective experience of remembering is less affected,” Rugg said. “Indeed, older individuals are more likely than young people to report a strong sense of recollection in association with memories.”

The researchers will investigate the potential causes of this age-related dissociation between objective and subjective measures of episodic memory.

“If our predictions about the different effects of TMS in young and older people are fulfilled, it will add significantly to our understanding of why memory becomes more error-prone as we grow older.

Dr. Michael Rugg,
director of UT Dallas’
Center for Vital Longevity

Rugg, who also is a professor in the School of Behavioral and Brain Sciences, said older people are at a greater risk than the young of making decisions based on memories that feel accurate but are, in fact, incorrect. The NIA-funded project will use fMRI in concert with transcranial magnetic stimulation (TMS) to investigate the neural underpinnings of post-retrieval monitoring.

Post-retrieval monitoring refers to the cognitive processes that operate on information that has been retrieved from memory, evaluating whether the information is relevant to the task at hand and, if so, how it should be used. Monitoring is heavily dependent upon the brain’s prefrontal cortex, a region that is highly vulnerable to advancing age.

“To our knowledge, this will be the first time that TMS has been used to investigate the influence of age on memory monitoring,” Rugg said. “If our predictions about the different effects of TMS in young and older people are fulfilled, it will add significantly to our understanding of why memory becomes more error-prone as we grow older.”

In previous work, Rugg and his colleagues were surprised to find that brain networks support the monitoring function to the same extent in young and older adults.

They now predict that age-related impairment in monitoring will be more evident when these networks are stressed. That can be evaluated either by imposing extra processing demands on the networks or by their temporary disruption through neurostimulation with TMS, which uses a magnetic coil to briefly disrupt the function of a small patch of the cortex.

“Cognitive decline steepens as people reach their late 60s,” Rugg said. “In light of the rapidly increasing proportion of the population entering older age, research into the causes and mediators of age-related cognitive decline is a high priority. We are excited to have received this support, which will enable us to take our research in memory and aging in new and innovative directions.”