November 08, 2007

Brain Yields Clues to False Memories

THURSDAY, Nov. 8 (HealthDay News) -- The areas of the brain where memory is processed may determine how a person can be absolutely certain of a past event that never occurred, otherwise known as a "false memory," say Duke University Medical Center researchers.

They used functional magnetic resonance imaging (fMRI) to analyze the brain activity of volunteers as they performed tests of both memory and false memory.

Those who were highly confident of memories that were indeed true showed increased activity in the medial temporal lobe (MTL), which focuses on specific facts about an event. Participants who were highly confident that false memories were true showed increased activity in the frontal parietal network (FPN), which processes the general idea of an event.

"Human memory is not like computer memory -- it isn't completely right all the time," study senior author and neuroscientist Roberto Cabeza said in a prepared statement. "There are many occasions when people feel strongly about past events, even though they might not have occurred."

The findings, published in the Journal of Neuroscience, could help improve understanding of age-related memory changes or lead to new tools for early diagnosis of Alzheimer's disease.

"Specific memories don't last forever, but what ends up lasting are not specific details but more general or global impressions," Cabeza said. "Past studies have shown that as normal brains age, they tend to lose the ability to recollect specifics faster than they lose the ability to recall impressions. However, patients with Alzheimer's disease tend to lose both types of memories equally, which may prove to be a tool for early diagnosis."

More information

The American Academy of Family Physicians has more about memory loss.

-- Robert Preidt
SOURCE: Duke University Medical Center, news release, Nov. 6, 2007
id=609795