With Age, The Focus Of Memory Shifts From The Specific To The General - Research

We are all afraid of getting older and losing our memory. Indeed, the phrase “memory is the first thing that leaves” is supported by research. A new study, however, questions this fact, arguing that memory is more difficult than it seems. And the focus of memory shifts with age.

Zachariah Reagh, an assistant professor at the University of Washington, has studied the brain activity of the elderly. Instead of the usual experiments, when subjects are asked to pronounce a group of words or memorize a chain of numbers, he analyzed brain activity using a "naturalistic approach" - exploring possibilities against a background that looked more like real activity.

He found that brain activity in older adults is not necessarily weaker when it comes to memory. “She's just different,” he said. The research results are published in the journal Nature Communications

General memory tests measure a person's ability to memorize a sequence of words, count backwards, or recognize repetitive images. “How often do you think a 75-year-old man needs to remember 'tree, apple, cherry, truck'?” Rei asks.

Instead, he used a dataset from the Cambridge Center for Aging and Neurology, which included functional MRI scans of people watching an 8-minute film. “There were no specific instructions or pitfalls,” Rey said. "They just needed to relax and enjoy the movie."

But while the subjects relaxed, their brains worked hard to recognize, interpret, and classify the events in the film. One way people categorize what is happening is by marking boundaries where one event ends and another begins.

An "event" can be anything, says Rey. “This conversation or part of it. We take these significant parts and extract them from the continuous flow. " These boundaries are constant for people. “If you and I are watching the same movie and are instructed to press a button when we feel that a significant block is over, our responses will be the same in most cases, not different,” says Rey.

When looking at fMRI results, which measure changes in blood flow and blood oxygen to determine brain activity, older adults showed the same increased activity in setting event boundaries. This does not mean that the brain of any age processes information in the same way. “It's different,” Ray said. “In some areas, activity is decreasing, and in some it is even increasing.”

Overall activity does decline between 18 and 88 years, Rey said. “But we found several areas where activity increased with age. It was unexpected. We saw differences in levels of activity in the hippocampus that were associated with memory in another dimension - historical memory. The focus of memory is shifting.

"Broadly speaking, the hippocampus's response to event boundaries can predict how well you are at analyzing and remembering stories and complex narratives, regardless of age." But in older people, activity in the area closer to the front of the brain, especially in the medial prefrontal cortex, was higher. This area is associated with broad, schematic, generalized knowledge, such as what it is like to go to a grocery store in general, as opposed to a specific grocery store.

“It is possible that as older people lose some sensitivity in the posterior regions of the brain, they may move away from more detailed contextual information,” Rey said. But as the level of activity in the anterior regions increases, "everything becomes more schematic, closer to the point."

In practice, this can mean that the 20-year-old setting the boundaries of the events in the film may be more focused on the details: what particular room the characters are in, what is the exact content of the conversation.

The older viewer has a different focus of memory, he will pay more attention to the larger picture. What room are the characters in? Did the characters go from a formal dinner setting to a more relaxed afternoon setting? Has a loud, tense conversation turned into a friendly one?

“An interesting conclusion can be drawn: perhaps healthy older people are not overlooked. The point is not that information is not received, it is simply that it acts differently. "

• Author: Rick Nauert, PhD
• psychcentral.com/news/2020/08/17/memory-focus-shifts-from-specifics-to-generalities-as-we-age/158804.html