“Memory is the first thing to go.”
Everyone has heard it, and decades of research studies seem to confirm it: While it may not always be the first sign of aging, some faculties, including memory, do get worse as people age.
It may not be that straightforward.
Zachariah Reagh, assistant professor of psychological and brain sciences in Arts & Sciences at Washington University in St. Louis, looked at the brain activity of older people not by requiring them to recite a group of words or remember a string of numbers. Instead, Reagh looked at a “naturalistic approach,” one that more closely resembled real-world activities.
He found that brain activity in older adults isn’t necessarily quieter when it comes to memory.
“It’s just different,” he said.
The study results were published today in the journal Nature Communications.
Common tests of memory involve a person’s ability to remember a string of words, count backward, or recognize repeated images. “How many times do you suspect a 75-year-old is going to have to remember, ‘tree, apple, cherry, truck?’” asked Reagh, first author on the paper with Angelique Delarazan, Alexander Garber and Charan Ranganath, all of University of California, Davis.
Instead, he used a data set from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) that included functional MRI (fMRI) scans of people watching an 8-minute movie. “There were no specific instructions, or a ‘gotcha’ moment,” Reagh said. “They just got to kick back, relax and enjoy the film.”
But while they may have been relaxing, the subjects’ brains were hard at work recognizing, interpreting and categorizing events in the movies. One particular way people categorize events is by marking boundaries — where one event ends and another begins.