Neuroscientists left the lab to study memory loss. The results were surprising

One of the major cognitive changes that happens as we age is difficulty recounting details of past experiences. But two recent studies suggest that older adults’ memories may be richer than previously thought.

The notion that describing previous experiences becomes more difficult with age was built on decades of lab research, says Matthew Grilli, a psychologist at the University of Arizona in Tucson. Lab-based studies of autobiographical memories, which typically involved experimenters interviewing people about past events, have shown that older adults can recall fewer details than younger adults. Researchers have found this effect to be more pronounced in people with dementia, leading many to view this shift as a sign of cognitive decline.

Grilli and his colleagues wanted to test if the data held outside the lab. In a study that’s been accepted for publication in the Journal of Experimental Psychology: General, the researchers asked 24 young adults between the ages of 18 and 28 and 50 older adults between the ages of 61 and 81 to download a smartphone app that randomly recorded 30-seconds of audio five times per hour for 14 hours a day. After 10 continuous days of recording, the researchers sifted through those sound files for moments when people shared autobiographical memories and analyzed the content of those recollections. Participants also came into the lab for more traditional, in-person interview-based assessments.

The team found that in everyday conversations, older adults showed no significant difference in their ability to recount details compared with their younger counterparts. These findings suggest that researchers “may need to take a step back from the assumptions that we make about how autobiographical memories may or may not change in older age based on laboratory research, which might not be capturing the whole picture,” Grilli says.

These results are supported by another study, published January in PNAS, in which Grilli and his colleagues assessed autobiographical memory recall in more than 1,900 adults between 18 and 89 years of age using a different smartphone-based technique, which pinged participants throughout the day to ask about their thoughts. There, the team found that older adults reported their past thoughts with more specificity and vividness than their younger counterparts.

Researchers aren’t sure why these differences between the lab and everyday life only appear to show up in older adults. Jessica Andrews-Hanna, a cognitive neuroscientist at the University of Arizona and a coauthor of both studies, says one reason may be that the laboratory context is less familiar to older participants than to younger ones, who are often students on the campus where this type of work is carried out. On top of that, experimenters are often young adults themselves, meaning older adults may feel the need to provide more background context before describing the contents of their memories.

It’s still unclear whether the participants’ memories were accurate, Andrews-Hanna says. However, she adds, it may be that the way that people privately experience and share their memories in everyday life are more sensitive markers of disease-related cognitive decline than the accuracy of the descriptions themselves.

“We need more studies on aging that go outside the laboratory and look at memory and related function in a more naturalistic context,” says Daniel Schacter, a psychologist at Harvard University who was not involved in the work. Factors such as a person’s narrative style can also explain differences in autobiographical recall reported in the lab, he says.

Brian Levine, a scientist at the Baycrest Academy for Research and Education in Toronto who wasn’t involved in this work, emphasizes that aging does indeed affect memory — difficulty remembering the details of past episodes is one of the most common complaints of aging — but the way older adults use their memories may differ from the way younger adults do. “When we bring them into the lab and test them on things that are not optimized to their needs, then they’re going to look more impaired than they really are,” he says.