Study: Brain's "Dream Network" Functions Differently in Alzheimer's Patients

People in the early stages of Alzheimer's disease appear to turn on areas of the brain that are normally active during periods of passive daydreaming, according to a study reported in the Nov. 25 in the Proceedings of the National Academies of Science.

The findings could provide a clear and powerful new method for diagnosing individuals in the very early stages of Alzheimer's disease.

Using functional magnetic resonance imaging, researchers at Washington University in St. Louis compared the thought patterns of young adults and older adults without Alzheimer's disease and adults experiencing early signs of the disease.

Specifically, the researchers examined regions of the brain that are active when the brain has no particular task at hand and regions that operate when the mind is free to wander and daydream.

The study revealed surprising differences in the ability of younger and older adults to shut down a brain network normally active during periods of passive daydreaming, according to the researchers.

"What we found in our study is that rather than turning these regions off when asked to concentrate, as young adults do, people with Alzheimer's seem to turn them on," said researcher Cindy Lustig, a post-doctoral fellow in psychology at the university.

Lustig said the finding might reflect a "broken brain" in Alzheimer's patients or, more optimistically, an attempt to compensate for the memory problems that come with the disease.

"In the long run, this quirk may help us understand what's going wrong with fundamental cognitive processes that underlie mental declines associated with aging and Alzheimer's," said Lustig. "In the meantime, we're very interested in whether these changes can be used to identify older adults in the earliest stages of Alzheimer's disease so that they can begin treatment as soon as possible."

Other sources: Washington University