November 24, 2020
In a recent Baycrest study examining people’s ability to recall details surrounding past events, research participants scored an average of 94% on memory accuracy. This high level of accuracy was observed regardless of the participant’s age or the amount of time that had elapsed since the event took place.
“This study shows us that memory accuracy is actually quite good under normal circumstances, and it remains stable as we age,” says Dr. Brian Levine, senior scientist at Baycrest’s Rotman Research Institute (RRI) and professor of psychology and neurology at the University of Toronto. “These results will be helpful for understanding memory in healthy aging.”
“These results are surprising to many, given the general pessimism about memory accuracy among scientists and the prevalent idea that memory for one-time events is not to be trusted,” says Dr. Nicholas Diamond, the study’s lead researcher, former graduate student at the RRI and current postdoctoral researcher at the University of Pennsylvania. In fact, about 400 academics (including memory scientists) surveyed as part of this study estimated memory accuracy to be around 40% at best, expecting this score to be even lower for older participants or with greater amounts of time elapsing since the events.
“This pessimism originates from earlier studies showing that memory can be manipulated using certain testing methods,” says Dr. Levine. “While those studies were important in showing the ways in which memory can fail, we wanted to know what happens when people freely recall events without such manipulation. We found that they are overwhelmingly accurate.”
In the study, which was published in Psychological Science, the researchers created an immersive, scientifically controlled event for their participants: a 30-minute audio-guided tour of art and other items displayed at Baycrest. Two days later, participants were asked to tell the researcher everything they could remember about the tour. The responses were recorded and then verified against the facts.
The researchers also tested Baycrest employees on their recall of a standardized, scripted procedure that they had experienced one month to three years prior. This allowed the researchers to examine the effect of delay between the event and memory recall, while the standardized nature of the procedure made it possible to verify accuracy. Using standardized, verifiable events to test memory is an innovative approach, as scientists typically use artificial laboratory stimuli, such as random word lists, rather than real-life experiences, or they test participants’ memory for personal past experiences, which cannot be verified.
The results showed that participants’ accuracy was high in both cases, though, as expected, the number of details they remembered decreased with age and time. At best, they recalled about 25% of their experience. Says Dr. Diamond: “This suggests that we forget the majority of details from everyday events, but the details we do recall correspond to the reality of the past.” Generally speaking, these results mean that the stories we tell about past events are accurate, even if details fade with time and age.
In a related study also published in Psychological Science, Drs. Diamond and Levine examined the degree to which people’s memories matched the true order of events. In this case, younger adults tended to perform better than older adults, suggesting that while accuracy of details remains high with age, older adults are less likely to correctly remember the true sequence of past events. That is, the order of our memories becomes disorganized as we age.
“The results of these studies can contribute to identifying differences in memory among those who develop dementia,” says Dr. Levine.
This work was made possible with support from the Canadian Institutes of Health Research (CIHR).
Future research will compare memory for another immersive, real-world experience in healthy adults and those with mild cognitive impairment with various amounts of time elapsed.
With additional funding, the researchers could design other controlled events and examine brain responses during recall to further examine the factors that affect memory accuracy.
Baycrest is a global leader in geriatric residential living, healthcare, research, innovation and education, with a special focus on brain health and aging. Baycrest is home to a robust research and innovation network, including one of the world’s top research institutes in cognitive neuroscience, the Rotman Research Institute; the scientific headquarters of the Canadian Consortium on Neurodegeneration in Aging, Canada’s largest national dementia research initiative; and the Baycrest-powered Centre for Aging + Brain Health Innovation, a solution accelerator focused on driving innovation in the aging and brain health sector. Fully affiliated with the University of Toronto, Baycrest provides excellent care for older adults combined with an extensive clinical training program for the next generation of healthcare professionals. Through these initiatives, Baycrest has remained at the forefront of the fight to defeat dementia as our organization works to create a world where every older adult enjoys a life of purpose, inspiration and fulfilment. Founded in 1918 as the Toronto Jewish Old Folks Home, Baycrest continues to embrace the long-standing tradition of all great Jewish healthcare institutions to improve the well-being of people in their local communities and around the globe. For more information please visit: www.baycrest.org
About Baycrest’s Rotman Research Institute
The Rotman Research Institute at Baycrest is a premier international centre for the study of human brain function. Through generous support from private donors and funding agencies, the institute is helping to illuminate the causes of cognitive decline in seniors, identify promising approaches to treatment and lifestyle practices that will protect brain health longer in the lifespan.