What really happened: brain study looks at false memories.

Got this from MSN.

The areas of the brain that process memories may determine why someone can be certain of a past event that never occurred, according to a new study published Tuesday.

The discovery could help doctors better assess the changes in memory that accompany aging and possibly lead to breakthroughs in the diagnosis of Alzheimer's disease, said the study's lead author, neuroscientist Robert Cabeza of Duke University Medical Center.

Trying to understand why some people can be so confident about false memories, Cabeza and his colleagues carried out MRI scans of the brains of healthy volunteers as they took memory tests.

The brain scans showed that volunteers who had accurate memories of an event showed increased activity in the medial temporal lobe (MTL) at the base of the brain, which focuses on facts about a past event.

"This would make sense, because the MTL, with its wealth of specific details, would make the memory seem more vivid," said Cabeza, whose article appeared in the Journal of Neuroscience.

"For example, thinking about your breakfast this morning, you remember what you had, the taste of the food, the people you were with. The added richness of these details makes one more confident about the memory's truth."

Volunteers who were confident in memories that turned out to be false showed increased activity in the impressionistic front parietal network (FPN) at the base of the brain, which tends to process the general meaning of an event without the details.

"Human memory is not like computer memory -- it isn't completely right all the time," said Cabeza. "There are many occasions when people feel strongly about past events, even though they might not have occurred."

The researchers used functional MRI in the study, an imaging technique that shows what areas of the brain are used during specific mental tasks. Cabeza worked with Hongkeun Kim at Daegu University in South Korea on the study, which was supported by the US National Institutes of Health and Daegu University.

The study results along with other research shows that as humans age their brains lose the ability to recall facts faster than the capacity to recall more general impressions, Cabeza said.

"Specific memories don't last forever, but what ends up lasting are not specific details, but more general or global impressions," Cabeza said.

"However, patients with Alzheimer's disease tend to lose both types of memories equally, which may prove to be a tool for early diagnosis," he said.