Brain scans show root of memory glitch with aging

MALCOLM RITTER, AP Science Writer

NEW YORK – Brain scans of older people in a noisy lab

machine give biological backing to the idea that 

distraction hampers memory with aging, researchers

reported Wednesday.

The finding bolsters a theory about one reason why

memory weakens with age: older people have more

trouble remembering some things because they're more

easily distracted when they try to learn them.

The memory exercise reported in the latest issue of the

Journal of Neuroscience dealt with recognizing faces, but

the findings apply to the more general task of trying to

remember something a person sees or hears, said lead

author Dale Stevens.

Stevens, a postdoctoral researcher at Harvard University,

did the work while at the Rotman Research Institute at

Baycrest, which is affiliated with the University of

Toronto.

Older people who have to learn something should do all

they can to focus on that task and eliminate potential

distractions, he advised.

The study compared 10 healthy people in their 60s and

70s to a dozen younger volunteers, ages 22 to 36. Their

brains were scanned while they looked at photographs of

people they did not know. As each photograph was

displayed for one second, the volunteers were asked if

they'd seen it before in the study.

In all they saw 180 different faces, of which 120 showed

up a second time. The older participants failed to

recognize a face they'd already seen 43 percent of the

time, compared to 26 percent for the younger volunteers.

Researchers went back to see what was going on in the

brains of the volunteers when they first saw a face that

they later failed to recognize. Why didn't those faces get

planted in memory?

In both groups, a brain area called the hippocampus,

which is involved in memory, was less active when a face

failed to stick in the memory than when it did. That was no

surprise. More interestingly, the older group also showed

heightened activity in certain other brain areas while the

younger volunteers did not.

Those areas included the auditory cortex, which plays a

role in analyzing sound, and several areas involved in

directing attention, Stevens said.

So what was going on? The brain-scanning machine was

noisy, with lots of knocking, buzzing and banging like a

jackhammer, Stevens said. Even with the earplugs the

volunteers wore, "it's a little distracting," he said.

The brain activity in the older volunteers shows that the

noise was more distracting to them than to the younger

participants, and reveals the brain circuits involved,

researchers concluded.

The study could not address when a person's brain starts

to act up this way. But Cheryl Grady of the Rotman

institute, another author, said she suspects it may begin

between ages 40 and 60.

Dr. Barry Gordon, a neurology professor and memory

expert at The Johns Hopkins Medical Institutions in

Baltimore, called the work "an appreciable advance." A

next step could be seeing whether older people will do

better on a memory test if they're warned about the

distraction problem, said Gordon, who wasn't involved in

the new study.

In any case, he said, "if you want to remember something,

it's more important if you're older than younger not to be

listening to your iPod."

On the Net:

The Journal of Neuroscience: http://www.jneurosci.org/

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http://news.yahoo.com/s/ap/20081126/ap_on_sc/sci_aging_memory