Aging and middle-age people’s forgetfulness might not mean their cognition is waning or even that their memories are slowing down or fading—just that they’re spending their cognitive energies elsewhere, in places that don’t happen to be “where did I leave the keys?” and “what’s that word again?”
These findings come from a study published in the journal Neuroimage that examined 112 people between the ages of 19 and 76. Participants were asked to recall specific details of images of faces. As might be expected, those between 19 to 35 did better in recalling those details, such as which side of the screen a particular face popped up on or the order in which they appeared. But it’s not because the older people’s brains weren’t working as well.
"This may not be a 'deficit' in brain function per se, but reflects changes in what adults deem 'important information' as they age,” study author Natasha Rajah, PhD, said in a statement.
Their brains were just working differently. According to MRI scans taken during the study, the brains of participants 60 and older lit up around the medial prefrontal cortex instead of the visual cortex.
According to study authors, this could mean that older people are using a different part of their brains to make up for slowdowns in other parts, or it could just mean that older people were paying attention to different information than the younger individuals, causing them to use different brain processes.
Not allocating energy toward those everyday memory functions can still have negative impacts, even if such consequences aren’t necessarily proof of a decaying mind.
"This change in memory strategy with age may have detrimental effects on day-to-day functions that place emphasis on memory for details such as where you parked your car or when you took your prescriptions," Rajah said.