"In young adults, there are parts of the brain that are very active during a passive free-thinking state, but these areas appear to shut down dramatically or 'turn off' when the person is asked to do something," said Cindy Lustig, research team member and post-doctoral fellow in psychology at Washington University in St. Louis. "Interestingly, older people, especially those with Alzheimer's disease, don't show this same kind of brain activity during free- thinking, resting conditions."
In a study published Nov. 25 in the Proceedings of the National Academies of Science, Lustig and colleagues detail results of functional magnetic resonance imaging (fMRI) tests conducted on groups of young adults, older adults and adults experiencing early signs of Alzheimer's-related dementia.
Although fMRI testing is widely used to track regional increases in brain activity during completion of specific mental tasks, such as language, memory or problem solving, this study focuses on what happens in regions that are active when the brain has no particular task at hand, regions that are focal points for a baseline, passive processing mode, one that seems to operate when the mind free to wander and daydream.
"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," Lustig said. "This might reflect a 'broken brain' in
Alzheimer's, making it hard for peo
'"/>
Contact: Gerry Everding
gerry_everding@wustl.edu
314-935-6375
Washington University in St. Louis
25-Nov-2003