Health and Medical News and Resources

General interest items edited by Janice Flahiff

Aging memories may not be ‘worse,’ just ‘different’

From The August 20, 2020 news release of the Washington University in St. Louis

Excerpts
“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…..

….Much of the activity he was interested in is in an area of the brain referred to as the posterior medial network — which includes regions in the midline and toward the backside of the brain. In addition to memory, these areas are heavily involved in representing context and situational awareness. Some of those areas showed decreased activity in the older adults.

We do think the differences are memory-related,” Reagh said. At the boundaries, they saw differences in the levels of activity in the hippocampus that was related to memory in a different measurement — “story memory,” he called it.

“There might be a broad sense in which the hippocampus’s response to event boundaries predicts how well you are able to parse and remember stories and complex narratives,” no matter one’s age, Reagh said.

But for older adults, closer to the front of the brain, particularly the medial prefrontal cortex, things were looking up.

Activity in that area of the brain was ramped up in older adults. This area is implicated in broad, schematic knowledge — what it’s like to go to grocery store as opposed to a particular grocery store.

“What might be happening is as older adults lose some responsiveness in posterior parts of the brain, they may be shifting away from the more detailed contextual information,” Reagh said. But as activity levels heighten in the anterior portions, “things might become more schematic. More ‘gist-like.’”

In practice, this might mean that a 20-year-old noting an event boundary in a movie might be more focused on the specifics — what specific room are the characters in? What is the exact content of the conversation? An older viewer might be paying more attention to the broader picture — What kind of room are the characters in? Have the characters transitioned from a formal dinner setting to a more relaxed, after-dinner location? Did a loud, tense conversation resolve into a friendly one?

“Older adults might be representing events in different ways, and transitions might be picked up differently than, say, a 20-year-old,” Reagh said.

“An interesting conclusion one could draw is maybe healthy older adults aren’t ‘missing the picture.’ It’s not that the info isn’t getting in, it’s just it’s getting in differently.”

August 17, 2020 Posted by | biology | , , , | Leave a comment

Brain Structure Adapts To Environmental Change

From the 14 June 2011 Medical News Today article

Scientists have known for years that neurogenesis takes place throughout adulthood in the hippocampus of the mammalian brain. Now Columbia researchers have found that under stressful conditions, neural stem cells in the adult hippocampus can produce not only neurons, but also new stem cells. The brain stockpiles the neural stem cells, which later may produce neurons when conditions become favorable. This response to environmental conditions represents a novel form of brain plasticity. The findings were published online in Neuron on June 9, 2011….

June 14, 2011 Posted by | Medical and Health Research News | , , , , | Leave a comment

   

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