The good surprises of memory: it does not decline so much with age and it is useful for understanding the future

Memory is as much about the future as it is about the past. Diving into our memories allows us to better anticipate the future and age has no real influence in this process. These are the findings of two separate new studies that looked at memory. The two works somewhat modify our previously established beliefs about memory, its role in apprehending the future and its accuracy in the elderly.

Remember to better understand

Our memories help us navigate our future experiences. American researchers from Washington University in St. Louis found that the more a memory is first encoded, the easier it is for a person to notice subsequent changes and understand them. In their work, published on November 23 in the review Proceedings of the National Academy of Sciences (PNAS), they studied participants’ brains using MRIs while they answered questions about movies that depicted an actor’s day-to-day life. Each new film represented a new day in the life of the actor with each time slight changes. The volunteers were brought to remember what happened in the films of the day before. Three days later, participants were asked to recall what happened in the second film and if it is different from the first.

Classic memory theory suggests that the more forcefully a person encoded the first movie, the more they interfere with conflicting information from the second day if the actor did something different. This experiment showed the opposite. When participants showed more brain activity at the end of day one while watching day two, they were more likely to notice a difference in the second movie. “This illustrated memory retrieval was happening in real timeobserved Jeffrey Zacks, author of the study. When people watched the second film, they didn’t just encode it or form new memories. They were retrieving what happened in the first movie by watching the second movie, integrating the two and using the retrieval to guide understanding.”

Surprising results

The second study came to bring a touch of hope to aging people: our memories retain a remarkable fidelity with reality, regardless of age, as long as the person is in good health. The researchers noted a surprising accuracy of 94%, even taking into account age, in the restitution of past events. “These results are surprising to many, given the general pessimism regarding memory accuracy and the widespread belief that memory for point events is untrustworthy.”, rejoiced Nicholas Diamond, principal researcher of the study.

The team of American and Canadian researchers created an immersive, scientifically controlled event for their attendees: a 30-minute audio-guided tour of artwork and other exhibits at Baycrest, a research and education for the elderly. Two days later, participants were asked to say anything they could remember from the tour. Responses were recorded and then fact-checked. The researchers also tested hospital employees on their recall of a visit experienced one month to three years previously. This allowed them to examine the effect of the delay between the event and memory recall.

The results showed that participants’ accuracy is high in both cases. A slight decrease in the restitution of details was observed with age and time. At best, participants recalled about 25% of their experience. “This suggests that we forget the majority of details of daily events but the details we remember correspond to the reality of the past.”, retained Nicholas Diamond. “This study shows us that memory accuracy is actually quite good under normal circumstances and remains stable with age.continues Brian Levine, co-author on the study. These results will be useful for understanding how memory works in healthy aging people..”