For a long time, memory lapses were considered an almost inevitable consequence of aging. But neuroscientists at Binghamton University offer a more subtle explanation: with age, the brain does not necessarily forget more. Above all, it would be more difficult to put the right elements together.
The researchers followed 61 adults aged 18 to 74. Participants had to memorize associations between faces and objects or scenes, then find the correct combination a few minutes later, while their brain activity was observed by MRI.
The result is striking: young adults found the correct association in 36% of cases, compared to 24% among 50-60 year olds and 20% among 61-74 year olds.
The brain remembers… but sometimes mixes the right elements
Imagine a search engine that finds the correct memory, but attaches the wrong file to it. This is precisely what seems to be happening.
Older participants often recognized images presented previously, but had more difficulty finding the precise link between them.
© Image Credit: Figure 1. Overview of the experiment. Reprinted from Mekbib and McDonough (2026), Cerebral Cortex, 36(7), bhag114, https://doi.org/10.1093/cercor/bhag114, used under CC BY-NC 4.0..
“This becomes difficult because all these images displayed on the screen during the test seem familiar to them. They know they’ve seen them before, but what they need to remember now is the specific connection. And that’s where, as we age, the mistakes really start to show themselves.”explains Ian McDonough, professor of psychology at Binghamton University.
Researchers studied how the hippocampus, a structure essential to memory, reactivates memories. In young adults, good reactivation of brain traces was associated with better performance. Among older participants, it was almost the opposite:
the more strongly certain memory patterns were reactivated, the more association errors there were.
Middle age could be a real turning point
One of the major takeaways from the study is that this change doesn’t seem to start only in old age.
“There is a significant decline in memory accuracy in people aged 20 to 30, and into their 50s. Some hippocampal processes already begin to decline in mid-life. This suggests that midlife is truly a time of transition.”underlines Ian McDonough.
Middle age thus appears to be a pivotal period, still largely neglected by research on brain aging.
Another surprise: researchers did not observe a major difference between groups in complete forgetting. It was especially associative memory errors that increased.
And contrary to popular belief, the phenomenon cannot be explained solely by a reduction in the volume of the hippocampus. It is also the way the brain organizes and reactivates information that seems to change.
Memory failures that do not necessarily mean illness
Participants were healthy and did not have diagnosed dementia. The study therefore describes changes associated with aging, and does not allow us to say that these errors announce a neurodegenerative disease.
For researchers, the challenge now is to better understand what happens during this intermediate period of life. Future work could notably explore the effect of brain stimulation or neurofeedback on the consolidation and retrieval of memories.
“We don’t yet have a good scientific understanding of what happens in midlife, because the brain does not decline uniformly during this period; some regions are declining faster than others“, McDonough said. “It will be important to determine when these tipping points occur“.
In other words, searching for a name for a few seconds or confusing the place where you met someone may not only be a sign that the memory is fading. This could be a quieter sign that the way our brains classify memories is already changing.