Scientists say a lifetime of knowledge clutters older people's memories.

A new study suggests that because the brains of older adults allocate more space to knowledge accumulated over the years, they have more material to sift through when attempting to access memories. 

This may explain why remembering becomes more of a challenge with age. 

While this wealth of prior knowledge can make memory retrieval challenging, the researchers say it has its upsides - life experience can aid with creativity and decision-making.

Researchers in the US and Canada looked at several behavioural and neuroimaging studies, which show that older adults have difficulty suppressing information that is no longer relevant and that when searching for a specific memory, they often retrieve other, irrelevant memories along with it. 

The studies also showed that when given a cognitive task, older adults rely more heavily on previous knowledge than younger adults do.

While the researchers focused primarily on the difficulties that these cluttered memories may pose, they also highlight a few situations in which these crowded memoryscapes may be useful. 

“Evidence suggests that older adults show preserved, and at times enhanced, creativity as a function of enriched memories,” the researchers wrote. 

They further hypothesise that older adults may be well served by their prior knowledge when it comes to decision-making, where they can pull on their accumulated wisdom.

With continued study and increased understanding of how memory works in older adults, researchers are hopeful that they may be able to find new ways to help them. 

“It is possible that the increased binding and richer encodings of older adults can even be leveraged to improve older adults’ learning and memory,” the new study says. 

The full report is accessible here.